PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
Browse
12 results
Search Results
Article A Comparative Study on Hydroxyl and Ether Functionalized Ionic Liquid Additives for Defect Passivation and Stability in Perovskite Solar Cells(Royal Soc Chemistry, 2025) Siyahjani Gültekin, S.; Turgut, S.B.; Ozdemir, Saliha; Gültekin, B.; Varlikli, C.This study systematically investigates the effects of two ionic liquid (IL) additives, 2-(2-methoxyethoxy)-N,N-bis(2-(2-methoxyethoxy)ethyl)-N-methylethanaminium iodide (EtAI) and 2-hydroxy-N,N-bis(2-hydroxyethyl)-N-methylethanaminium iodide (HOAI), on the structural, morphological, optical, and photovoltaic properties of triple-cation perovskite thin films. FT-IR, XRD, XPS, SEM, and AFM analyses were employed to characterize additive-induced modifications, while UV-Vis, PL, and TRPL measurements were utilized to evaluate their optical properties. SEM and AFM results reveal that the hydroxyl (-OH) groups in HOAI and etheric groups in EtAI significantly improve film morphology by enhancing grain size, reducing surface roughness, and refining grain boundaries, thereby promoting more efficient charge transport. Photovoltaic characterization revealed that the film with 3 mmol HOAI exhibited a maximum reverse-scan power conversion efficiency (PCE) of 17.65%, retaining approximately 85% of its initial efficiency after 1000 hours under ambient conditions. In contrast, the film with 1 mmol EtAI achieved a reverse-scan PCE of 17.17%, although higher EtAI concentrations adversely affected stability. These findings provide valuable insights into the interplay between additive chemistry and perovskite film quality, offering a promising route for improving the efficiency and long-term performance of perovskite solar cells. This record is sourced from MEDLINE/PubMed, a database of the U.S. National Library of MedicineArticle Creatinine-On Colorimetric Elisa-Based Serum Creatinine Detection in a Microfluidic Device(Royal Soc Chemistry, 2025) Karakuzu, Betul; Tekin, H. CumhurChronic kidney diseases (CKDs), which often end in kidney failure for many people around the world, have an important place in public health given that they also trigger other diseases. Therefore, the development of fast and cost-effective diagnostic technologies enables effective monitoring of patients and early diagnosis. Here, using the Enzyme-Linked Immunosorbent Assay (ELISA) principle, serum creatinine concentrations were determined using the developed lab-on-a-chip (LOC) platform. In this system, which was termed "creatinine-on-a-chip", colorimetric ELISA protocol was applied to determine creatinine levels in a microfluidic chip functionalized with creatinine-specific antibodies. Creatinine detection was performed by quantifying the absorbance difference between the detection and reference channels, normalized to the reference signal within the microfluidic chip. The detection signal intensity varied depending on the region selected along the microfluidic channel. The adsorption of the capture antibody used for surface functionalization, which was particularly more pronounced near the inlet region, played a critical role in the detection signal. These findings suggest that random selection of the detection area can lead to significant signal variability, and that careful selection of a well-characterized region is essential for improving detection performance. With this developed system, creatinine was detected with high sensitivity in the linear range of 1-20 mu g mL-1, both spiked in phosphate buffered saline (PBS) and fetal bovine serum (FBS). Using the creatinine-on-a-chip, serum creatinine analysis can be performed rapidly (similar to 15 min) in a cost-effective manner ($1.05 per test).Article Citation - WoS: 1Citation - Scopus: 1Understanding the Role of a Specific Microenvironment in Personal Exposure To Semi-Volatile Organic Compounds Using Silicone Wristbands(Royal Soc Chemistry, 2025) Akmermer, Zulfikar; Demirtepe, HaleAssessment of personal exposure to semi-volatile organic compounds was facilitated using silicone wristbands (SWBs), an easy-to-use sampler that reflects total inhalation and dermal exposure from all the microenvironments and the activities in which the user was involved. Hence, SWBs help understand exposure from various routes, activities, and microenvironments. Offices are critical microenvironments where workers spend one-third of their daily time on weekdays; hence exposure from offices should be more extensively studied. This study aimed to investigate the personal exposure of university personnel and elaborate on the contribution of the exposure due to the office air to their overall exposure using SWBs. One SWB was worn by the participant, and another was hung in their office. After seven days of sampling on the wrist, exposure to polycyclic aromatic hydrocarbons (PAHs) was found to be related to combustion activities at home or from open fire, whereas exposure to organophosphate esters and phthalates was suggested to originate from building materials, such as flooring materials and paints, and consumer products, e.g. mattresses and furniture. PAHs in the participants' offices were influenced by the transport of outdoor air and phthalates from the ceiling material. Then, we estimated the equivalent air concentrations using the SWBs sampled from the offices and previously developed sampling rates and partition coefficients. The estimated office air exposure contributions to total inhalation and dermal exposure were 83%, 51%, and 39% for fluorene, tri(n-butyl) phosphate, and tris(2-chloro isopropyl) phosphate, respectively. These findings were consistent with the statistical analysis of personal data. To conclude, this study highlighted the importance of specific microenvironments in our exposure to particular SVOCs, offering strategies for indoor air quality management and human health risk assessment.Article Citation - WoS: 3Citation - Scopus: 3A Novel MIP Electrochemical Sensor Based on a CuFe2O4NPs@rGO Nanocomposite and Its Application in Breast Milk Samples for the Determination of Fipronil(Royal Soc Chemistry, 2025) Njjar, Muath; Akturk, Ezgi Zekiye; Kaya, Ahmet; Onac, Canan; Akdogan, AbdullahBackground: fipronil, a widely utilized insecticide in agriculture, has been shown to have potential health implications as it can accumulate in the environment and affect human health. Electrochemical sensors, specifically those incorporating molecularly imprinted polymers (MIPs), provide an efficient way for the detection of fipronil because of their selectivity and specificity. The combination of CuFe2O4NPs and reduced graphene oxide (rGO) exhibits a synergistic effect that enhances sensitivity and selectivity. The composite's effective properties provide a robust platform for fipronil determination in various matrices. This study detected fipronil using an electrochemical sensor based on a glassy carbon electrode (GCE) modified with MIP@CuFe2O4NPs@rGO. Results: the synthesized MIP@CuFe2O4NPs@rGO material was characterized using various techniques such as Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (FESEM), X-ray diffraction (XRD) analysis, energy dispersive X-ray (EDX) analysis, Brunauer-Emmett-Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS) analysis, and electrochemical impedance spectroscopy (EIS). The modified GCE showed enhanced electrochemical behavior for fipronil, as demonstrated by cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. Optimization of parameters such as pH, pyrrole concentration, and template concentration further improved sensor performance. The sensor exhibited a linear dynamic range of 1 to 6 nM, with a limit of detection (LOD) of 0.30 nM (S/N = 3) and a limit of quantification (LOQ) of 1.08 nM (S/N = 10), highlighting its sensitivity and reliability. The precision of the method was excellent, with a relative standard deviation of less than 4.0%. When applied to quantify fipronil in breast milk samples, the sensor showed high accuracy and precision, with recoveries ranging from 96.24% to 97.75%. Significance: the sensor offers several advantages, including high sensitivity, specificity, and accuracy. Its ability to detect fipronil in complex matrices such as breast milk highlights its potential for real-world applications in environmental and health monitoring. Overall, this research paves the way for the development of efficient, rapid and eco-friendly sensors for detecting pesticide residues in various environmental and biological samples.Article Citation - WoS: 1Citation - Scopus: 1Phase-Dependent Optical, Photocatalytic and Capacitive Properties of Tungsten Oxide Nanowires(Royal Soc Chemistry, 2025) Kahraman, Zeynep; Gungor, Ahmet; Buldu-Akturk, Merve; Tan, Metin; Alp, Emre; Erdem, Emre; Genc, AzizTransition metal oxides hold great promise across a wide range of applications due to favorable properties such as high abundance, low toxicity, and excellent stability. Nanoengineering approaches are essential for controlling the structural, optical, and electronic properties of these materials, enabling the achievement of desired characteristics in a cost-effective and environmentally friendly manner. In this study, we synthesize stoichiometric (WO3) and sub-stoichiometric (WO3-x) tungsten oxide nanowires by controlling their phases and morphologies through the hydrothermal method. This approach allows us to systematically investigate the effects of different phases and oxygen vacancies on the optical properties, as well as on photocatalytic and supercapacitance applications. We use the photodegradation of RhB as a benchmark for photocatalytic activity under various experimental conditions, revealing that oxygen vacancies significantly influence photocatalytic behavior. For example, WO3-x nanowires adsorb/degrade a substantial amount of RhB within short durations under ambient conditions, where WO3 nanowires are mostly inactive. The addition of H2O2 enhances the photocatalytic performance of WO3 nanowires over 30 minutes, with even better results under low pH conditions with H2O2. This study also explores the phase-dependent electrochemical properties of WO3 and WO3-x nanowires, providing insights into their potential for improved supercapacitor performance by leveraging their complementary properties in symmetric and asymmetric configurations. WO3-x, with a higher density of oxygen vacancies and thinner structure, offers enhanced conductivity and increased active sites for charge storage, resulting in superior specific capacitance and charge retention.Article Citation - WoS: 3Citation - Scopus: 4Magsity Platform: a Hybrid Magnetic Levitation-Based Lensless Holographic Microscope Platform for Liquid Density and Viscosity Measurements(Royal Soc Chemistry, 2025) Ince, Oyku Doyran; Tekin, H. CumhurThe viscosity and density of liquids are the most extensively studied material properties, as their accurate measurement is critical in various industries. Although developments in micro-viscometers have overcome the limitations of traditional bulky methods, more accessible technologies are required. Here, we introduce a novel magnetic levitation-based method to measure the viscosity and density of solutions in a microcapillary channel. This principle exploits microparticles as microsensors to correlate levitation time and height with solutions' viscosity and density, using buoyancy and drag forces. The platform has an integrated lensless holographic microscope, providing a hybrid system for in situ and precise measurements. By utilizing this hybrid technology, portable, rapid and cost-effective measurements can be conducted. This platform enables viscosity and density measurements within 7 minutes, achieving high accuracies of at least 97.7% and 99.9%, respectively, across an operation range of 0.84-5.09 cP and 1.00-1.09 g cm-3. The platform is utilized to clearly distinguish differences in the spent cell culture medium across various cell lines. This method, as presented, can be readily applied to measure a diverse array of liquids in multiple domains, encompassing biotechnology, medicine, and engineering.Article Citation - WoS: 2Citation - Scopus: 3Dynamic Fluidic Manipulation in Microfluidic Chips With Dead-End Channels Through Spinning: the Spinochip Technology for Hematocrit Measurement, White Blood Cell Counting and Plasma Separation(Royal Soc Chemistry, 2025) Oksuz, Cemre; Tekin, Hüseyin Cumhur; Bicmen, Can; Tekin, H. CumhurCentrifugation is crucial for size and density-based sample separation, but low-volume or delicate samples suffer from loss and impurity issues during repeated spins. We introduce the "Spinochip", a novel microfluidic system utilizing centrifugal forces for efficient filling of dead-end microfluidic channels. The Spinochip enables versatile fluid manipulation with a single reservoir for both inlet and outlet functions. It expels compressed air, facilitating fluid flow, and offers programmable filling mechanisms based on the hydraulic resistance of microfluidic channels. Compatible with a basic centrifuge, it allows sequential filling, internal mixing, and collection in straight microfluidic channels by simply adjusting the spinning speed, eliminating the need for complex valving. We demonstrated the Spinochip's efficacy in blood testing, where it successfully separated blood components, such as plasma, buffy coat, and red blood cells, from a single drop using centrifugation alone. This system enabled simultaneous hematocrit (R2 >0.99) and total white blood cell (R2 >0.93) quantification within a single microfluidic channel without the need for staining or special reagents. Remarkably, the Spinochip can perform hematocrit measurements on as little as 100 nL of blood, potentially paving the way for less invasive blood analysis. This innovative approach unlocks new possibilities in microfluidics, providing precise fluidic control and centrifugation for sample volumes as small as a few nanoliters.Article Citation - WoS: 4Citation - Scopus: 4Tailored Bodipy-Based Fluorogenic Probes for Phosgene Detection: a Comparative Evaluation of Recognition Sites(Royal Soc Chemistry, 2024) Dartar, Suay; Kaya, Beraat Umur; Yayak, Yanki Oncu; Vural, Ezgi; Emrullahoglu, MustafaWe constructed two novel boron-dipyrromethene (BODIPY)-based fluorescent probes, BOPD and BOBA, each equipped with the phosgene specific recognition units o-phenylenediamine (OPD) and o-aminobenzylamine (OBA) at the 2-position of the BODIPY core. BOPD and BOBA represent rare examples of BODIPY-based probes that operate by modulating an intramolecular charge transfer process (ICT), as validated by computational studies. We systematically compared the analytic performance of those recognition units while focusing on selectivity, fluorescence turn-on ratios and response times. Probe BOBA, equipped with OBA as the recognition unit, demonstrated a remarkably low detection limit (i.e., 1.40 nM) and a rapid response time (<10 s) for triphosgene. By comparison, BOPD, featuring an OPD unit, showed superior selectivity towards triphosgene, with a detection limit of 93 nM and a response time of up to 30 s. A portable sensing platform was developed by loading BOPD onto test strips made of TLC plates, nonwoven materials and small-headed cotton swabs, which were assessed for their effectiveness in detecting phosgene. We additionally performed the first successful application of a fluorescent probe, namely BOPD, for monitoring the accumulation of phosgene in plants.Review Citation - WoS: 10Citation - Scopus: 12Trends in Authentication of Edible Oils Using Vibrational Spectroscopic Techniques(Royal Soc Chemistry, 2024) Ozen, Banu; Cavdaroglu, Cagri; Tokatli, FigenThe authentication of edible oils has become increasingly important for ensuring product quality, safety, and compliance with regulatory standards. Some prevalent authenticity issues found in edible oils include blending expensive oils with cheaper substitutes or lower-grade oils, incorrect labeling regarding the oil's source or type, and falsely stating the oil's origin. Vibrational spectroscopy techniques, such as infrared (IR) and Raman spectroscopy, have emerged as effective tools for rapidly and non-destructively analyzing edible oils. This review paper offers a comprehensive overview of recent advancements in using vibrational spectroscopy for authenticating edible oils. The fundamental principles underlying vibrational spectroscopy are introduced and chemometric approaches that enhance the accuracy and reliability of edible oil authentication are summarized. Recent research trends highlighted in the review include authenticating newly introduced oils, identifying oils based on their specific origins, adopting handheld/portable spectrometers and hyperspectral imaging, and integrating modern data handling techniques into the use of vibrational spectroscopic techniques for edible oil authentication. Overall, this review provides insights into the current state-of-the-art techniques and prospects for utilizing vibrational spectroscopy in the authentication of edible oils, thereby facilitating quality control and consumer protection in the food industry. The authentication of edible oils has become increasingly important for ensuring product quality, safety, and compliance with regulatory standards.Article Citation - WoS: 1Anisotropic Structural, Vibrational, Electronic, Optical, and Elastic Properties of Single-Layer Hafnium Pentatelluride: an <i>ab Initio</I> Study(Royal Soc Chemistry, 2024) Dogan, Kadir Can; Cetin, Zebih; Yagmurcukardes, MehmetMotivated by the highly anisotropic nature of bulk hafnium pentatelluride (HfTe<INF>5</INF>), the structural, vibrational, electronic, optical, and elastic properties of single-layer two-dimensional (2D) HfTe<INF>5</INF> were investigated by performing density functional theory (DFT)-based first-principles calculations. Total energy and geometry optimizations reveal that the 2D single-layer form of HfTe<INF>5</INF> exhibits in-plane anisotropy. The phonon band structure shows dynamic stability of the free-standing layer and the predicted Raman spectrum displays seven characteristic Raman-active phonon peaks. In addition to its dynamic stability, HfTe<INF>5</INF> is shown to exhibit thermal stability at room temperature, as confirmed by quantum molecular dynamics simulations. Moreover, the obtained elastic stiffness tensor elements indicate the mechanical stability of HfTe<INF>5</INF> with its orientation-dependent soft nature. The electronic band structure calculations show the indirect-gap semiconducting behavior of HfTe<INF>5</INF> with a narrow electronic band gap energy. The optical properties of HfTe<INF>5</INF>, in terms of its imaginary dielectric function, absorption coefficient, reflectance, and transmittance, are shown to exhibit strong in-plane anisotropy. Furthermore, structural analysis of several point defects and their oxidized structures was performed by means of simulated STM images. Among the considered vacancy defects, namely , , V<INF>Te<INF>out</INF></INF>, V<INF>Te<INF>in</INF></INF>, , and V<INF>Hf</INF>, the formation of V<INF>Te<INF>out</INF></INF> is revealed to be the most favorable defect. While and V<INF>Hf</INF> defects lead to local magnetism, only the oxygen-substituted V<INF>Hf</INF> structure possesses magnetism among the oxidized defects. Moreover, it is found that all the bare and oxidized vacant sites can be distinguished from each other through the STM images. Overall, our study indicates not only the fundamental anisotropic features of single-layer HfTe<INF>5</INF>, but also shows the signatures of feasible point defects and their oxidized structures, which may be useful for future experiments on 2D HfTe<INF>5</INF>.