Sarac, M.F.; Solakyildirim, T.; Teber, A.

In this study, vertically aligned TiO2 nanowires (NWs) were fabricated on titanium (Ti) foil via thermal oxidation and subsequently coated with zinc oxide (ZnO) using zinc acetate solutions of 25, 50, and 100 mM concentrations. Structural and optoelectronic properties were systematically investigated using SEM, XRD, XPS, PL, UV-Vis, and I-V analyses. SEM results confirmed a progressive ZnO surface coverage, with complete encapsulation observed at 100 mM. EDS analysis revealed a Zn content increase from 0.81 wt.% (25 mM) to 8.43 wt.% (100 mM), accompanied by a decrease in Ti content from 70.78 wt.% to 49.02 wt.%. XRD patterns showed distinct ZnO peaks for coated samples, while XPS confirmed Zn2+ and Ti4+ states with minimal interdiffusion. Optical bandgap values increased slightly with ZnO concentration: 3.04 eV (pure TiO2), 3.06 eV (25 mM), 3.05 eV (50 mM), and 3.11 eV (100 mM), attributed to enhanced crystallinity and heterojunction formation. PL spectra showed increasing green luminescence (∼520 nm) with ZnO content, indicating rising defect-related recombination. Electrical measurements showed a sharp rise in photocurrent from 3.67 × 10−6 A (pure TiO2) to 4.74 × 10−4 A (100 mM). Correspondingly, responsivity (R) increased from 0.020 to 2.168 mA/W and detectivity (D*) from 8.5 × 108to 7.56 × 109 Jones. These results demonstrate that ZnO coating substantially enhances light absorption, charge separation, and carrier transport properties of TiO2 NWs. The optimized 100 mM ZnO-TiO2 heterostructure offers high-performance UV photodetection potential for environmental sensing, wearable optoelectronics, and aerospace technologies.

Gumus, Seyhmus; Kanberoglu, Gulsah Saydan; Kaya, Nurcan; Coldur, Fatih

Lidocaine is the most commonly used local anesthetic and can be used to reduce the feeling of pain caused by the stability of the nerve membrane and the pain that occurs at the end of the nerve signals in the skin. Due to the fact that lidocaine overdose causes side effects, determination of lidocaine is of great importance. The present study presents the development of a novel, simple, low-cost and reliable PVC membrane lidocaine hydrochloride-selective potentiometric sensor based on MIL-53(Al) metal organic framework (MOF) as a selective sensing functional material. The proposed sensor exhibited a linear potentiometric response for lidocaine hydrochloride in the concentration range of 1.0 × 10−7M−1.0 × 10−1M with the potential change of 55.4 mV/decade and a detection limit of 5.0 × 10−8M. The response time and the pH working range of the sensor were determined as 10 s and 2.37–7.45, respectively. These performance characteristics denote that the potentiometric lidocaine hydrochloride-selective sensor has quite superior properties. The potentiometric application of the lidocaine hydrochloride-selective sensor was successfully applied in pharmaceutical preparations.