The year of 2024 has been an inspiring chapter for the İTÜ Chemistry Department, marked by exceptional achievements and collaborative endeavours. From publishing impactful research in top-tier journals, our department members and students have continued to elevate the department’s reputation for excellence. These milestones reflect our unwavering dedication to advancing chemical science and fostering a vibrant academic community, paving the way for even greater accomplishments as we look ahead to 2025.
A novel study on silane's impact on surface and mechanical properties of polyurethane coating
Prof. Dr. Nilgün Kızılcan and her team showcase groundbreaking advancements in polyurethane coatings in a high-impact study published in 'Advanced Materials Interfaces' (Q1, IF: 6.38). Their research, featured on the back cover, delves into the transformative effects of varying the silane additive ratio, specifically TMSCH, on the surface and mechanical properties of coatings. This pioneering work not only enhances scratch resistance and hydrophobic traits but also sets new standards for coating applications in household appliances and beyond.
Continuous development in the formulation and processing techniques of polyurethane (PU) coatings improves an aesthetic appearance as well as protection against environmental factors. In this study, the formulation of PU coating with polyethylene glycol 600 (PEG600), isophorone diisocyanate (IPDI), and trimethoxysilylpropylcarbamoyloxyhexane (TMSCH) silane-based additive is optimized to obtain high scratch-resistant coating. An addition of 43.1 wt.% TMSCH in PU formulation resulted in a significant improvement in the scratch resistance and wettability properties compared with pure PU film. The homogenously prepared micron-thick coatings are characterized using scanning electron microscopy analysis and Fourier transform infrared spectroscopy. The results confirm the presence of silane additives in the PU coating matrix. The mechanical properties improved due to the increased crosslinking networks via the formation of urethane bonds by increasing the TMSCH in PU formulation. Prepared PU coating showed combined features of transparency, hydrophobicity, scratch resistance, and mechanical strength that make it a promising candidate for household appliances.
To access full article, https://onlinelibrary.wiley.com/doi/10.1002/admi.202300944
Biodegradable, Fluorescent PBAE: A Dual-Functional Photosensitizer for Targeted Cancer Therapy and Imaging
Recently, Kahveci and his research group have been developed, a water-dispersible, biodegradable and fluorescent poly(β-amino ester) (PBAE) based photosensitizer (PS) for efficient photodynamic therapy (PDT) and imaging. The polymeric PSs demonstrated significant anti-cancer potential as evaluated via reactive oxygen species generation, photocytotoxicity, colony formation and cell invasion assay.
This paper presents the development of a biodegradable, highly water-dispersible, and fluorescent poly(β-amino ester) (PBAE) designed as an efficient photosensitizer (PS) for photodynamic therapy (PDT) and imaging. Synthesized through aza-Michael addition-based poly-condensation polymerization, the PBAEs feature amine end groups and are end-capped with folic acid to enhance cancer-cell-targeting efficiency. These polymers form globular nano-sized particles for passive tumor targeting and demonstrate significant anti-cancer activity against U87-MG brain tumor cells and HeLa cervical tumor cells without significant cytotoxicity to non-cancer cells. The anti-cancer mechanism involves singlet oxygen and reactive oxygen species (ROS) generation upon red light irradiation, which reduces colony formation and prevents cancer cell invasion. Additionally, these polymers are highly effective in cancer cell imaging, making them a promising dual-functional tool for cancer treatment and diagnostics.
To access full article, https://doi.org/10.1039/D4PY00318G
Eco-Friendly PLA Enhanced with Caffeic Acid for Antioxidant and Antimicrobial Applications
Kahveci and his research group have been successfully grafted caffeic acid onto PLA-b-PHEMA polymer. Grafted copolymer exhibited antimicrobial and antioxidant properties. Films were prepared by combining commercial PLA with different proportions of PLA-b-PHEMA-g-CA using a solvent casting method. Both grafted copolymer and films exhibited antioxidant property and antimicrobial effect against S. aureus and E. coli, showcasing potential applications in sustainable materials.
Kahveci and his research group underscores the importance of enhancing poly(lactic acid) (PLA), an eco-friendly alternative to petroleum-based plastics derived from renewable sources like corn starch and sugarcane. While PLA lacks inherent functional groups, limiting its applications, this study addresses this by grafting a bioactive compound, caffeic acid, onto a poly(D,L-lactide)-b-poly(2-hydroxyethyl methacrylate) block copolymer (PLA-b-PHEMA). The resulting copolymer, PLA-b-PHEMA-g-CA, exhibits significant antioxidant and antimicrobial properties against S. aureus and E. coli, as confirmed by various characterization techniques. By blending this grafted copolymer with commercial PLA to produce films, the study demonstrates the potential for creating sustainable materials with enhanced functional properties, paving the way for innovative applications across diverse fields.
To access full article, https://doi.org/10.1016/j.eurpolymj.2024.113056
Innovative pH-Responsive Delivery System to Combat Antimicrobial Resistance
Kahveci and his research group have been developed a pH-responsive antibiotic delivery system based on pH-responsive poly(β-amino ester) (PBAE) and enzyme responsive hyaluronic acid (HA). The polymeric nanocomplexes were obtained via electrostatic complexation of PBAE and HA in the presence of a model antibiotics, colistin and vancomycin. The nanocomplexes released the drugs more at pH 5.5 compared to pH 7.4. Antibacterial activity of the system was evaluated on various bacteria. The nanocomplex loaded with the antibiotics exhibited significantly greater efficacy against E. coli and S. aureus.
The World Health Organization (WHO) identifies antimicrobial resistance (AMR) as a severe global threat to health, food security, and development. Efforts to combat AMR include educating individuals, implementing new policies, and developing novel antimicrobials and materials for effective delivery. Among these, innovative drug delivery systems that enable local and on-demand antibiotic release are particularly promising. This study introduces a pH-responsive antibiotic delivery system using poly(β-amino ester) (PBAE) and enzyme-responsive hyaluronic acid (HA). These polymeric nanocomplexes, formed through electrostatic complexation with model antibiotics colistin and vancomycin, exhibit size ranges of 131–730 nm at pH 7.4, which increase significantly at pH 5.5. The drug release performance, tested with FITC-labeled antibiotics, showed enhanced release at the acidic pH of 5.5. Antibacterial activity assays demonstrated that these nanocomplexes are significantly more effective against E. coli and S. aureus, highlighting their potential as a robust strategy for combating AMR through targeted and efficient antibiotic delivery.
To access full article, https://doi.org/10.1016/j.ijbiomac.2023.129060
A Novel Use of Thienothiophene (TT) and Single-Wall Carbon Nanotube (SWCNT) as High-Performance Supercapacitor
Prof. Turan Öztürk and coworkers’ report, for the first time, use of thienothiophene (TT) and single wall carbon nanotube (SWCNT) based free-standing and flexible hybrid material (TT-TPA-SWCNT) as a high-performance supercapacitor. The synthesized TT derivative, TT-TPA, was directly attached to SWCNT through non-covalent interactions to obtain the TT based SWCNT hybrid, TT-TPA-SWCNT as a flexible film. The TT-TPA-SWCNT supercapacitor displayed a high specific capacitance of 83.2 F·g-1 at 5 mV·s-1, a maximum power density of 3000 W·kg-1 and an excellent retention capacity of 110% up to 7000 charge/discharge cycling stability.
Prof. Turan Öztürk and coworkers’ paper introduces a novel hybrid material, thienothiophene (TT) and single-walled carbon nanotube (SWCNT) composite (TT-TPA-SWCNT), as a high-performance supercapacitor. This flexible and free-standing electrode demonstrates an impressive energy storage capacity of 83.2 F g−1 at a 5 mV s−1 scan rate, exceptional cyclic stability with 110% retention after 7000 cycles, and a wide power density range of 100 to 3000 W·kg−1. Advanced characterization methods reveal its promising structure, positioning TT-TPA-SWCNT as a significant advancement in energy storage systems for diverse applications.
To access full article, https://pubs.acs.org/doi/full/10.1021/acsaem.3c02737.
Prof. Turan Öztürk's Team Unveils Dual-Channel TTM Fluorescent Probe for Highly Sensitive ClO− Detection
Prof. Turan Öztürk and coworkers report, a novel TTM fluorescent probe bearing fluorobenzene substituted thienothiophene, thiophene and malononitrile units for highly sensitive and selective detection of ClO-. To literature, this report is one of the rare examples of a dual-channel (optical and electrochemical) probe with a turn-on mechanism.
This paper highlights the development of a novel probe, TTM, which combines thienothiophene and malononitrile units for the exceptionally selective and sensitive detection of hypochlorite (ClO−). As ClO− is a crucial reactive oxygen species in biological systems, with roles in both natural defense and potential oxidative damage when in excess, the need for a reliable detection method is paramount. TTM addresses this need with a rapid “turn-on” fluorescence response in under 30 seconds, naked-eye colorimetric detection, and voltammetric read-out with an anodic scan. The probe's low detection limit and applicability in real water samples and living cells make it a significant advancement. This study is notable for being one of the few examples utilizing a small thienothiophene-based molecule for both optical and electrochemical detection of ClO− in aqueous media.
To access full article, https://www.sciencedirect.com/science/article/pii/S0039914023012961
A Novel Investigation into the Impact of Microplastics on Bacterial Activity in Seawater Under the Influence of Climate Change
Prof. Dr. Aslı BAYSAL and her colleagues’ study reveals the significant impact of microplastics (MPs) on bacterial activity and biofilm formation in seawater, especially under varying temperature conditions influenced by climate change. It highlights how temperature variations can alter bacterial responses, oxidative characteristics, and biochemical reactions, shedding light on the complex interactions between MPs and marine bacteria. The differential responses of antioxidant systems in bacteria, the enhanced biofilm formation due to MP deformation, and the strong links between functional groups on MPs and bacterial responses underscore the ecological risks posed by MPs. Moreover, the research emphasizes the necessity for further investigations into the effects of environmental conditions on MP-microbe interactions, particularly in the context of global warming and extreme weather events. Understanding these dynamics is vital for developing effective strategies to mitigate the environmental impact of MPs and protect marine ecosystems.
Temperature changes due to climate change and microplastic contamination are worldwide concerns, creating various problems in the marine environment. The article “Culture dependent analysis of bacterial activity, biofilm-formation and oxidative stress of seawater with the contamination of microplastics under climate change consideration” corresponded by Prof. Dr. Aslı BAYSAL from Chemistry Department was published in the “SCIENCE OF THE TOTAL ENVIRONMENT” (Q1, IF: 10.94) aims to the impact of different temperatures of seawater exposed to different types of plastic materials on culture dependent bacterial responses and oxidative characteristics.
To access full article, https://www.sciencedirect.com/science/article/pii/S0048969724012427.
A groundbreaking research on oxidative stress, biofilm-formation and activity effects of microplastic-treated sediments on P. aeruginosa cells
The study which presented by Prof. Dr. Aslı BAYSAL and her colleagues addresses the globally emerging problems of microplastic (MP) contamination and temperature changes, highlighting their multifaceted impacts on environmental media. Unlike previous research focusing primarily on the direct effects of MPs, this study delves into the broader ecological implications, including the degradation, sorption, and subsequent changes in surrounding media. By examining MPs from various products and their interaction with anthropogenically affected sediments under different temperature conditions, the study reveals significantly different bacterial responses and biofilm formation. Notably, MPs from PET water bottles elicited higher metabolic responses and oxidative stress in sediments, underscoring the influence of sediment type on MP behavior. The research also demonstrates how climate change-induced temperature fluctuations can exacerbate MP contamination effects, leading to adaptive bacterial responses and enhanced biofilm formation. These findings emphasize the necessity for further investigation into the oxidative potential of different environmental media and the adaptive responses of microorganisms, including extremophiles, to MP contamination. Such comprehensive examinations are crucial for understanding and mitigating the environmental impact of MPs on marine and sediment ecosystems.
Climate change and plastic pollution are the big environmental problems that the environment and humanity have faced in the past and will face in many decades to come. Sediments are affected by many pollutants and conditions, and the behaviors of microorganisms in environment may be influenced due to changes in sediments. The article “Oxidative stress, biofilm-formation and activity responses of P. aeruginosa to microplastic-treated sediments: Effect of temperature and sediment type” corresponded by Prof. Dr. Aslı BAYSAL from Chemistry Department and founded by ITU was published in the “ENVIRONMENTAL RESEARCH” (Q1, IF: 8.88) aims to explore the differential effects of various microplastics and temperature on different sediments through the metabolic and oxidative responses of gram-negative P aeruginosa.
To access full article, https://www.sciencedirect.com/science/article/pii/S0013935124002536.
DFT Study on the His-Tag Binding Affinity of Metal Ions in Modelled Hexacationic Metal Complexes
The study conducted in the group of Prof. Dr. Mine Yurtsever sheds light on the structural dynamics of histidine oligomers (His-tags). His-tags are commonly used as affinity tags in recombinant protein purification to enable in vitro experimental studies, including biochemical and biophysical assays and structure determination.
Histidine, a natural amino acid, features an imidazole ring capable of forming various bonds, including pi–pi, hydrogen, cation-pi, and coordination bonds. Its oligomers, particularly hexamers, are widely employed as affinity tags in protein purification via immobilized metal affinity chromatography (IMAC). IMAC is an essential protein purification tool that is used widely for academic and industrial purposes. This process relies on the binding interaction between His-tags in recombinant protein sequences and the bivalent metal cation M2+ in the purification resin.
This study investigates the chemical structure and binding properties of metal-coordinating His-tags to uncover their metal-binding preferences and the structural changes induced by metal coordination. Using a model of hexahistidine oligomers, the research explores how these tags bind three bivalent metal ions between their imidazole rings, with coordination involving nitrogen atoms from the imidazole rings and oxygen atoms from the resin. Specifically, the study examines the binding properties of Ni²⁺, Cu²⁺, and Zn²⁺ in His-tag purification. The results show that Ni²⁺ exhibits the highest affinity for complexation with His6 and His6-AA, as indicated by enthalpy changes and interaction energy calculations. These findings provide insight into why nickel is preferred in experimental metal coordination studies, enhancing our understanding of His-tag purification. Stability was assessed by calculating relative energy changes upon metal binding. The findings offer insights into metal-induced conformational changes in His-tags and their impact on protein purification efficiency. These results hold potential for refining purification techniques, enhancing industrial applications, and advancing innovations in targeted biological delivery systems.
To access full article, https://pubs.acs.org/doi/full/10.1021/acsomega.4c05422
Investigating the Effect of GLU283 Protonation State on the Conformational Heterogeneity of CCR5 by Molecular Dynamics Simulations
Assist. Prof. Berna Doğan's latest article, published in the Journal of Chemical Information and Modeling, explores the impact of protonation states on the CCR5 receptor. Through all-atom molecular dynamics simulations, her research reveals how the protonation state of a single residue can influence the receptor's interaction profiles with binding partners, significantly affecting receptor function and drug design.
CCR5, a class A G protein-coupled receptor (GPCR), plays a crucial role as a coreceptor in facilitating HIV-1 entry into host cells. It is also essential to the immune system and contributes to the pathogenesis of various diseases. Numerous studies have been conducted to understand its activation mechanism, including structural investigations that revealed both the inactive and active states of the receptor when complexed with different binding partners. These structural insights have enabled molecular dynamics (MD) simulations to examine the conformational changes within the protein. Atomic-level dynamic studies further allow for the exploration of how ionizable residues affect the receptor's function.
In the study it was aimed to investigate the conformational changes in CCR5 when it forms a complex with either the inhibitor maraviroc (MRV), an approved anti-HIV drug, or HIV-1 envelope protein GP120, and compare these changes to the receptor’s apo form. This study used MD simulations to explore the conformational diversity of the CCR5 coreceptor, focusing on the impact of the protonation state of GLU2837.39, a key binding site residue. The results show that protonation significantly affects CCR5's ability to adopt active- or inactive-like conformations, especially when bound to GP120 or MRV. These findings highlight the role of GLU2837.39 in CCR5's structural dynamics and suggest potential implications for designing novel CCR5 inhibitors with higher binding affinity.
To access full article, https://pubs.acs.org/doi/10.1021/acs.jcim.4c00682
Manipulation of defect state emission in Zn chalcogenide quantum dots and their effects on chlorophyll spectral response
In the group of Assoc. Prof. Caner Ünlü, water-soluble Zn-based quantum dots (QDs) have been synthesized and their potential agricultural applications explored. These QDs are valued for their biocompatibility and low toxicity, making them highly suitable for biotechnology, especially in agriculture.
The study successfully controlled the defect-state emission of ZnSe QDs by creating a sulfur-rich outer layer around a selenium-rich core and modifying the capping agent. Gradient ZnSeS QDs were synthesized using different capping agents: 3-Mercaptopropionic Acid (3-MPA) and N-Acetyl-L- Cysteine (NAC). Furthermore, interactions between ZnSeS QDs and chlorophyll enhanced absorption and modulated spectral responses, suggesting potential applications in agriculture for optimizing light-harvesting processes and improving crop yields.
Zn-based QDs are nontoxic, easy to fabricate, and exhibit excellent photocatalytic activity due to their wide bandgaps. ZnSe QDs display dual emission—one from the crystal core due to quantum confinement and the other from surface defects. While these dual emission properties have been defined, manipulating these defects to control the emission has not yet been fully explored.
This study demonstrated that defect-state emission in ZnSe QDs could be effectively controlled by forming ZnSeS QDs with a gradient structure, consisting of a selenium-rich core and a sulfur-rich outer shell. The incorporation of sulfur significantly improved the photoluminescence quantum yield of ZnSeS QDs, surpassing that of ZnSe QDs, while also reducing emission from surface defects, indicating effective passivation. Both QDs were shown to interact with chlorophyll, boosting its absorption capacity.
The interaction also modulated the spectral response of chlorophyll, with variations depending on the composition of ZnSeS QDs. These findings underscore the potential of ZnSeS QDs in photonic applications and highlight the need for further research to optimize their use in light-harvesting systems.
To access full article, https://www.sciencedirect.com/science/article/pii/S1386142524015142
A Comparative study on the interaction between protein and PET Micro/Nanoplastics to provide an integrative view for micro/nanoplastic toxicity
Prof. Dr. Aslı BAYSAL and her colloquies published their research that can be insight for the effect of plastic pollution on living systems including human to microorganisms and presented their study in a prestigious journal in the field of toxicology of environmental pollutants.
The interaction between particles and proteins is a key factor determining the toxicity responses of contaminants. Therefore, this study aimed to examine the interaction between the emerging pollutant PET micro/nanoplastics from water bottles with bovine serum albumin. The structural characteristics of micro/nanoplastics revealed an interaction with protein. For instance, the assignment of protein-related new proton signals, changes in available protons, crystallinity, functional groups, elemental ratios, zeta potentials, and particle size of micro/nanoplastics were significantly observed after protein treatment. In addition, the loading and releasing of protein also showed similar responses with structural characteristics. Moreover, the cell-based responses were changed regarding the structural and surface characteristics of micro/nanoplastics and the loading efficiencies of protein. The findings are important regarding human health or the development of new biomaterials using structural characteristics of plastics.
To access full article, https://onlinelibrary.wiley.com/doi/10.1002/tox.24366
Prof. Dr. Barış Kışkan and his team completed their research that can be future application for polymer recycling, started with the late Prof. Dr. Yusuf Yağcı, and presented their work in a prestigious journal.
World-renowned and beloved late Prof. Dr. Yusuf Yağcı started a groundbreaking research project to solve one of the most important problems of our age: the recycling of plastics and their reintegration into the circular economy. After his premature and heartbreaking death, Prof. Dr. Barış Kışkan took responsibility for the project and with his dedicated team, completed the research successfully. They have published this groundbreaking work in ACS Sustainable Chemistry & Engineering with quite good impact factor of 7.9. The team was aimed to honoured Prof. Dr. Yusuf Yağcı's vision and legacy by dedicating this article to his memory.
Upcycling/recycling of waste polymers to reduce the exponentially increasing plastic pollution is an environmental subject of great importance. Accordingly, in this work, we propose the use of an “all-in-one” photolytic hydrogen atom transfer (photo-HAT) reagent (phenacyl bromide) that can in situ generate bromine radicals, acetophenone, HBr, and H2O2, resulting in a total of four well-established, potent intermediates for the photodegradation/photodepolymerization of waste polystyrene (PS) foam. Under ambient conditions, using ethyl acetate solvent and the stated photo-HAT catalyst, waste PS breaks down to oligomers with less than eight styrene units and to several organic compounds, such as aromatic ketones, oxygenated alkenes in conjunction with acetophenone and trace benzoic acid. A plausible reaction mechanism demonstrating the role of each in situ generated intermediate involved in this photodegradation is proposed. Herein, we present an efficient metal-free photo-oxidative degradation method for commercial PS using a cheap organic reagent at ambient sustainable conditions. Ultimately, this study provides a promising alternative to recent waste polymer valorization methods involving toxic transition metal salts and halogenated solvents.
To access full article, https://pubs.acs.org/doi/10.1021/acssuschemeng.4c02871
Comparative study of two MIP-based electrochemical sensors for selective detection and quantification of the antiretroviral drug lopinavir in human serum
Prof. Dr. Ayşegül Gölcü and her team successfully determined the amount of Lopinavir, an antiretroviral drug from the protease inhibitor class, in tablets and commercial serum samples using molecular imprinted polymer technology within the scope of a project they conducted with Prof. Dr. Sibel A. Özkan (Ankara University, Faculty of Pharmacy, Department of Analytical Chemistry). They confirmed their experimental studies with quantum chemical calculations made by Assoc. Prof. Dr. Taner Erdoğan (Kocaeli University, Kocaeli Vocational School, Department of Chemistry and Chemical Processing Technologies). They presented all their research in a respected journal.
Thermal polymerization (TP) and electropolymerization (EP) are the two methods used in this study to explore the molecular imprinting process. To detect the antiviral medication lopinavir (LPV), an inhibitor of enzyme HIV1 protease that is co-formulated with ritonavir (RTV) to extend its half-life in the body, with greater precision, these methods were merged with an electrochemical sensor. The sensors were created on glassy carbon elec trodes (GCE) based on molecularly imprinted polymers (MIP) using TP with methacrylic acid (MAA) functional monomer and EP with p-aminobenzoic acid (PABA) functional monomer. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and electrochemical methods were utilized to examine the technical features of the suggested sensors. For both approaches, the necessary optimization investigations were carried out. Different LPV concentrations, ranging from 1.0 pM to 17.5 pM in drug solution and commercial human serum samples, were used to validate the analytical efficiency of the two sensors and compare their electroanalytical behaviour. For the measurement of LPV in tablet form and serum samples, the proposed TP-LPV@MIP/GCE and EP-LPV@MIP/GCE sensors provide good recovery, demonstrating 99.85–101.16 % and 100.36–100.97 % recovery, respectively. The imprinting factor was utilized to demonstrate the selectivity of the suggested sensors by utilizing several anti-viral drugs that are structurally comparable to LPV. Additionally, the constructed sensors were examined for the potential impacts of interferences and the stability during the storage.
For more details: https://www.sciencedirect.com/science/article/abs/pii/S0039914024011706
Novel Imide-Yne Reaction Revolutionizes Polyimide Synthesis in X-Yne Click Polymer Chemistry
Günay and his colleagues have unveiled a new way to create advanced polymers using the imide-yne reaction, a method now applied to macromolecules for the first time. This innovative approach combines bisimides and dipropiolates at room temperature using a simple catalyst, DABCO, to produce linear poly(imide ester)s in high yields.
The polymers, with molecular weights between 5.64 and 12.67 kDa, feature unreacted double bonds that can be further modified. By adding thiols with the help of another catalyst, TBD, researchers created poly(imide thioether)s, demonstrating the material’s adaptability.
What makes this discovery stand out is the ability to customize the thermal properties of these materials, such as their glass transition temperatures and heat resistance. This flexibility could lead to a range of applications, from electronics to high-performance materials.
This new method is expected to make a big impact on polymer chemistry by offering a reliable and versatile tool for building next-generation materials.
For more details: https://doi.org/10.1039/D4PY00918E
Light-Induced Polymer Unlocks High-Performance Supercapacitor and Bioapplication Potential
Kaya and his colleagues discovered a new eco-friendly method to synthesize poly(guaiazulene) (PGz) has led to a high-performance supercapacitor (SC) electrode when combined with reduced graphene oxide (rGO). This PGz_rGO electrode outperforms commercial SCs with a specific capacitance of 258.6 F g⁻¹, energy density of 30.57 Wh kg⁻¹, and excellent cycling stability (94% after 5000 cycles).
Unlike harsh traditional methods, this simple photochemical approach uses light to process guaiazulene in a sustainable, cost-effective way. PGz’s unique structure and the addition of rGO enhance charge storage, ion transport, and durability, making it a game-changer for energy storage.
PGz’s versatility also extends to biomedicine, such as photodynamic therapy, and optoelectronics, thanks to its water solubility and optical properties. This innovation offers a greener, more efficient alternative for energy and biomedical applications.
For more details: https://doi.org/10.1002/aelm.202400570
Novel Thienothiophene-Carbon Nanotube Hybrid Delivers High-Performance Flexible Supercapacitors
Prof. Turan Öztürk and coworkers report, for the first time, use of thienothiophene (TT) and single wall carbon nanotube (SWCNT) based free-standing and flexible hybrid material (TT-TPA-SWCNT) as a high-performance supercapacitor. The synthesized TT derivative, TT-TPA, was directly attached to SWCNT through non-covalent interactions to obtain the TT based SWCNT hybrid, TT-TPA-SWCNT as a flexible film. The TT-TPA-SWCNT supercapacitor displayed a high specific capacitance of 83.2 F·g-1 at 5 mV·s-1, a maximum power density of 3000 W·kg-1 and an excellent retention capacity of 110% up to 7000 charge/discharge cycling stability.
For more details: https://doi.org/10.1021/acsaem.4c01457
Thienothiophene-Based AIE Materials Offer Highly Sensitive Detection of Explosives
Prof. Turan Öztürk and coworkers report, three thienothiophene based AIE active materials (TPE2-TT, TPE3-TT and TPE3-TPA-TT), possessing tetraphenylethylene and triphenylamine units, were designed and synthesized as chemosensors for sensitively detecting 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT) and trinitrophenol (TNP) explosives. Among the AIEgens, TPE3-TT demonstrated a maximum Stern-Volmer constant (Ksv) reaching to 2.9 x 104 M-1 by quenching response toward TNP. This study provides a new strategy to design fluorescent sensing molecules with high sensitivity and detection response.
For more details: https://doi.org/10.1016/j.jphotochem.2024.116095
Thienothiophene-Phthalocyanine Material Powers Flexible OFET Gas Sensors for NO₂ and SO₂ Detection
A novel thienothiophene (TT) and phthalocyanine (Pc) based conjugated material was designed, synthesized, fabricated for an organic field effect transistor and utilized as an OFET based gas sensor for hazardous gases such as NO2 and SO2 by Prof. Turan Öztürk and Prof. İsmail Yılmaz Research Groups. This novel OFET-based gas sensor provides new opportunities for the scalable production of high-performance flexible sensing electronics.
For more details: https://doi.org/10.1039/D4TC03208J
Thienothiophene-Anthracene Polymer Achieves Breakthrough Hydrogen Production for Energy Conversion
Herein, Prof. Turan Öztürk and Spanich IMDEA groups report a hyperbranched conjugated polymer, containing thienothiophene and anthracene units (TT-Ant), synthesized via Pd (0) catalyzed Suzuki coupling reaction. Its structural, photophysical and electrochemical features were investigated by UV-Vis, fluorescence spectroscopies, cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS). The photocatalytic hydrogen evolution tests, conducted combining the material with two different additives, resulted in high hydrogen production rates from water. A steady state production rate around 286 mmol g−1 h−1 for its hybridization with TiO2 was recorded, which is more than 3 times, compared to pristine TiO2 under the same conditions. Moreover, the combination of the polymeric material with platinum (1% wt) resulted in a maximum rate value of 700 mmol g−1 h−1. This work may provide a new strategy to construct stable photocatalysts with thienothiophene and anthracene cores as active sites for efficient catalytic reactions in energy conversion applications.
For more details: https://doi.org/10.1039/D4TC02568G
Molecular architecture of a novel indoline-fused chromenylium-cyanine probe carrying methionine biomolecule for ultrasensitive analyzing Hg2+ ion in real samples
Prof. Dr. İsmail YILMAZ and his team have developed a next-generation sensor platform (CSI) that absorbs and emits in the near infrared (NIR) region and have investigated its properties in this article. In addition, a study was carried out on a new Hg2+ sensor, CIME (L-methionine methyl ester and glyoxal-derivation of CSI), which operates in less than 30 seconds and has a wide working range.
In this study, by decorating the chromenylium-cyanine structure with an indoline ring, a new sensor platform CSI with a highly rigid structure and improved photophysical properties was developed for the first time. This study was published in Journal of Environmental Chemical Engineering (Impact Factor : 7.4) by Prof. Dr. İsmail YILMAZ and his team in December 2024. The CSI platform was modified with glyoxal and L-methionine methyl ester to produce a new NIR, ratiometric, and switch-on probe (CIME). This probe is biocompatible, water soluble, and has a specific binding mode for Hg2+ ion selectivity. The crystal structure of CSI was determined by x-ray crystallography (by Doç. Dr. Kerem Kaya), and its electronic characteristics, including HOMO-LUMO energy levels were determined by quantum mechanical calculations (by Prof. Dr. Nurcan Tüzün and Dr. Yılmaz Özkılıç). CIME is the first instance of an indoline-fused chromenylium-cyanine used for quantification of trace level of Hg2+ in both the living cells and the environment. The new probe has a high level of selectivity and sensitivity for Hg2+ in aqueous media, with broad linear ranges (0–300 μM for UV-Vis and 0–225 μM for fluorescence). It has a rapid response time of 30 seconds, and UV-Vis and fluorescence detection limits of 7.4 ng/mL and 0.13 ng/mL, respectively. Probe quantitatively detected Hg2+ in real samples using UV-Vis, fluorescence spectrophotometry and a smartphone. The interaction between CIME and Hg2+ was verified by FTIR, HRMS and DFT calculations. Furthermore, the ability of CIME to sense Hg2+ in living cells was confirmed in both MCF-7 cells and 3T3 cells (by Dr. Ayşe Buse Özdabak Sert).
This study was supported by Scientific and Technological Research Council of Turkey (TUBITAK) under the Grant Number 219Z085.
To access full article: https://doi.org/10.1016/j.jece.2024.114388
Reduced graphene oxide supported meso-pyridyl BODIPY-Cobaloxime complexes for electrocatalytic hydrogen evolution reaction
Prof. Dr. Esin Hamuryudan and her research team have published a study on reduced graphene oxide-supported meso-pyridyl BODIPY-Cobaloxime complexes for electrocatalytic hydrogen evolution reaction in the International Journal of Hydrogen Energy.
The study explores the development of advanced electrocatalysts for hydrogen evolution reactions, focusing on reduced graphene oxide-supported meso-pyridyl BODIPY-Cobaloxime complexes. These materials were synthesized and evaluated for their electrocatalytic performance, demonstrating high efficiency and stability in hydrogen production. The findings contribute to the advancement of sustainable and eco-friendly energy technologies. Creating innovative catalysts utilizing nonprecious metals for the electrocatalytic hydrogen evolution reaction (HER) poses a significant difficulty. Cobaloxime (Cox) complexes containing 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) moiety, pyridine (2-Cox) and tetrafluorophenyl-thio-pyridine (4-Cox) functional groups were successfully synthesized. The π–π stacking between the cobaloxime complex and reduced graphene oxide (rGO) immobilizes this combination, which acts as a catalyst for proton reduction. Both alkaline and acidic conditions were used to test the two rGO/2-Cox and rGO/4-Cox electrodes' electrocatalytic activities towards hydrogen (H2). When compared to alkaline conditions, the cobaloxime-modified rGO electrodes exhibit better electrocatalytic activity for the HER in conditions that are acidic.
To access full article: https://doi.org/10.1016/j.ijhydene.2024.09.284
Thienothiophene-Based AIE Materials Offer Highly Sensitive Detection of Explosives
Prof. Dr. Turan Öztürk and coworkers report, three thienothiophene based AIE active materials (TPE2-TT, TPE3-TT and TPE3-TPA-TT), possessing tetraphenylethylene and triphenylamine units, were designed and synthesized as chemosensors for sensitively detecting 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT) and trinitrophenol (TNP) explosives. Among the AIEgens, TPE3-TT demonstrated a maximum Stern-Volmer constant (Ksv) reaching to 2.9 x 104 M-1 by quenching response toward TNP. This study provides a new strategy to design fluorescent sensing molecules with high sensitivity and detection response.
For more details: https://doi.org/10.1016/j.jphotochem.2024.116095
Innovative Advances by Senkal’s Research Group: Efficient Lead Detection and Next-Generation Capacitor Technologies
Innovative Adsorbent Enables Efficient Lead Detection in Water and Edible Plant Extracts
Şenkal and her colleagues have developed an advanced method to detect and extract lead from water and edible plants, such as lettuce and dill, using a novel thiosemicarbazide-modified, sulfonamide-based poly(styrene) adsorbent (T-CSPS). This innovative adsorbent, synthesized through the reaction of chlorosulfonated polystyrene and thiosemicarbazide, was characterized using SEM–EDX, FT-IR, and zeta potential analyses. For the first time, T-CSPS was applied to dispersive solid-phase microextraction (d-SPµE) to isolate and preconcentrate lead (Pb II) ions in water and plant extracts under simulated digestive conditions (unified bioaccessibility method saliva solution). The optimized method achieved a recovery rate of 103% at pH 4 with just a 2-minute contact time, demonstrating high efficiency with a preconcentration factor of 15 and an adsorption capacity of 40 mg g−1. It also displayed exceptional sensitivity, with detection and quantification limits of 5.1 μg L−1 and 16.9 μg L−1, respectively, and precision values of 2.2% and 3.1% for intra-day and inter-day analyses. The method’s accuracy was validated using certified reference materials and spiked samples, highlighting its reliability. This breakthrough, employing flame atomic absorption spectrometry (FAAS) for lead detection, presents a fast, economical, and reliable solution for monitoring toxic metals in food and water, with significant implications for environmental safety, agriculture, and public health.
For more details: https://link.springer.com/article/10.1007/s12011-023-04001-7
Voltage-Responsive Carbon Dot/Polyaniline Composite Offers Breakthrough for Next-Gen Capacitors
Şenkal and her colleagues have successfully developed a novel carbon dot/polyaniline (CD/PANI) composite with remarkable voltage-dependent dielectric properties, paving the way for advanced capacitor applications. Synthesized via in-situ oxidative polymerization of aniline in the presence of carbon dots, the composite was meticulously characterized using spectroscopic (FT-IR), morphological (TEM, SEM), and electrical techniques.
Impedance analysis revealed the composite’s charge transport behavior across a frequency range of 500 Hz to 10 MHz at 25 °C, offering detailed insights into its dielectric properties. The dielectric constant of the CD/PANI composite increased significantly with applied voltage, reaching values of 6.97 at 0.5 V and 12.87 at 5 V for 1 kHz. The study further highlighted the material’s ability to reduce its dielectric constant with increasing frequency, showcasing its tunability as a voltage-dependent dielectric (VDD) material.
Additionally, current-voltage (I-V) measurements demonstrated the composite’s capacity for adjustable dielectric parameters under varying DC voltage, while its enhanced electrical conductivity underscored its potential for use in next-generation dielectric devices. These findings position the CD/PANI composite as a promising candidate for innovative capacitor technologies, offering enhanced performance and adaptability for modern electronic systems.
For more details: https://www.sciencedirect.com/science/article/pii/S2468023024016432