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Amoxicillin (AMX), one of the most commonly used antibiotic drugs, can cause overwhelming hazards if abused, particularly when it contaminates the environment and affects individuals. As a result, devising an easy and accurate method for estimating AMX content is vital. In this work, we describe a turn off/on detection method for Cr3+ and AMX using a smart pH-switchable ZnO quantum dot (QD) nanoprobe. The ZnO QDs were synthesized using tetraethyl orthosilicate (TEOS) as a capping agent through a simple low-temperature base-hydrolysis reaction. The TEOS-capped ZnO QDs exhibited strong fluorescence with a peak at 520 nm under excitation at 330 nm. Numerous methods, such as energy-dispersive X-ray (EDX), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), UV–vis absorption, and UV–vis reflectance, have been used to demonstrate the successful synthesis of TEOS-capped ZnO QDs. The lowest excited state exhibits selective fluorescence quenching and enhancement upon the addition of Cr3+ and AMX, respectively, in the presence of other interferences at pH 7 and pH 1 respectively (both in liquid and solid-state PL). The estimated LOD of 15.94 nM (in case of Cr3+) and 77.86 nM (in case of AMX) was achieved. The recovery of various concentrations of AMX in real samples ranged from 95% to 101.1%, with a relative standard deviation of 0.05–1% (n = 3). This work harnesses the specific and excellent performance of TEOS-capped ZnO QDs, contributing to further progress in the analytical and materials research fields. There is ample scope for using this nanoprobe in the fabrication of both pH sensors (owing to its pH-switching ability) and capacitive sensors (owing to the semiconducting nature of ZnO). [ABSTRACT FROM AUTHOR]

In general, defects are crucial in designing the different properties of two-dimensional materials. Therefore large variations in the electric and optical characteristics of two-dimensional layered molybdenum disulphide might be attributed to defects. This study presents the design of a temperature and nitrogen sensor based on few-layer molybdenum disulfide sheets (FLMS), which was developed from bulk MoS2 (BMS) through an exfoliation approach. The produced sulfur defect, molybdenum defect, line defect, and plane defect were characterized by scanning transmission electron microscopy (STEM), which substantially impacts the sensing characteristics of the resulting FLMS. Our theoretical analysis validates that the sulfur vacancies of the MoS2 lattice improve sensing performance by promoting effective charge transfer and surface interactions with target analytes. The FLMS-based sensor showed a high sensitivity for detecting nitrogen gas with a detection limit (LOD) of ~ 0.18 ppm. Additionally, temperature-detecting capabilities were assessed over various temperatures, showing outstanding stability and repeatability. To the best of our knowledge, this material is the first of its kind, demonstrating visible N2 gas sensing with chromic behaviour. [ABSTRACT FROM AUTHOR]

AC conductivity and dielectric relaxation of MoO3 doped V2O5–ZnO–CuO glass-nanocomposites have been studied in a wide temperature and frequency ranges. Electron microscopic studies reveal that Cu3O8V2 and Cu3Mo2O9 nanophases (for higher MoO3 content) have been developed, which are expected to form various defect states. Owing to formation of such nanophases, different values of maximum barrier height have been developed, which are supposed to play vital roles in the conduction process. Electric modulus formalism has been conceived as it can exclude the electrode polarization effect at low frequency regime and suggest the transition from long-range mobility to short-range mobility assembly of polarons. Correlated barrier hopping model and its modified version have been found to be most appropriate theoretical models to explore the conduction process. It is also noteworthy that relaxation times are found to increase with higher MoO3 content, which may indicate about the slow movement of charge carriers. The nature of variation of Kohlraush Williams Watts parameters can be considered as a tool to reveal the reason for shifting of relaxation process from Debye to Non-Debye type up to a limit with more and more incorporation of MoO3 content into the previous materials. By crossing the limiting value of composition (0.08 mol% of MoO3), it becomes non-Debye type at a very slow rate. Lower values of dielectric constant at high frequencies are expected to be important for their applications in photonics and opto-electronics. Scaling method of electric modulus spectra indicates that the dielectric relaxation process in the present system leads to a common relaxation process at various temperatures, but it is strongly dependent on compositions. [ABSTRACT FROM AUTHOR]

Metformin, the primary therapy for type 2 diabetes mellitus (T2DM), showed limitations such as varying absorption, rapid system clearance, required large amount, resistance, longstanding side effects. Use of Nano formulations for pharmaceuticals is emerging as a viable technique to reduce negative consequences of drug, while simultaneously attaining precise release and targeted distribution. This study developed a Polyethylene Glycol conjugated Graphene Oxide Quantum dots (GOQD-PEG) nanocomposite for the sustained release of metformin. Herein, we evaluated the effectiveness of metformin-loaded nanoconjugate in in vitro insulin resistance model. Results demonstrated drug loaded nanoconjugate successfully restored glucose uptake and reversed insulin resistance in in vitro conditions at reduced dosage compared to free metformin. [ABSTRACT FROM AUTHOR]

Physico-mechanical and dynamic mechanical properties of typical solution grade styrene-butadiene rubber (S-SBR) and polybutadiene rubber (PBR) based tiretread compound were investigated by partially replacing highly dispersible (HD) silica with naturally occurring [alpha]-cellulose. Fourier transform infrared spectrum detected abundance of hydroxyl group in [alpha]-cellulose, which has created keenness to investigate its reinforcement characteristics in an S-SBR and PBR based compound. Scanning electron microscope and transmission electron microscope were employed to investigate the microstructure and dispersion of [alpha]-cellulose at higher magnification. Thermo-gravimetric analysis was performed to understand the degradation behavior of [alpha]-cellulose. Differential scanning calorimeter was engaged to detect phase transition and degree of purity of [alpha]-cellulose. An increase in cure rate was observed with partial replacement of HD silica by [alpha]-cellulose. The cure rate index was increased by 13% over control one at 10% replacement of silica with [alpha]-cellulose. It was noticed that at an optimum level of replacement (10%), [alpha]-cellulose containing compounds exhibited lower viscoelastic energy dissipation (both loss modulus [E'] and loss tangent [tan [delta]]) at the slight expense of tensile moduli. Beside these, substitution of silica with [alpha]-cellulose found to have no effect on wet grip property of the compounds. KEYWORDS [alpha]-cellulose, HD silica, rubber-filler interaction, SBR rubber, tire-tread compound, 1 I INTRODUCTION As reinforcing fillers, carbon black (CB) and silica have been widely employed by various rubbers based industrial products, especially in the tire technology, due to their low [...]