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In the present investigation, copper benzene tricarboxylate metal organic frameworks (CuBTC MOF) and Au nanoparticle incorporated CuBTC MOF (Au@CuBTC) were synthesized by the conventional solvothermal method in a round bottom flask at 105 • C and kept in an oil bath. The synthesized CuBTC MOF and Au@CuBTC MOFs were characterized by structure using X-ray diffraction (XRD) spectroscopic methods including Fourier Transform Infrared spectroscopy, Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), and Energy dispersive spectroscopy (EDS). We also characterized them using morphological techniques such as Field emission scanning electron microscopy (FE-SEM), and electrochemical approaches that included cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). We examined thermal stability by thermogravimetric analysis (TG/DTA) and N 2 adsorption-desorption isotherm by Brunauer-Emmett-Teller (BET) surface area method. Both materials were tested for the detection of lead (II) ions in aqueous media. Au nanoparticle incorporated CuBTC MOF showed great affinity and selectivity toward Pb 2+ ions and achieved a lower detection limit (LOD) of 1 nM/L by differential pulse voltammetry (DPV) technique, which is far below than MCL for Pb 2+ ions (0.03 µM/L) suggested by the United States (U.S.) Environmental Protection Agency (EPA) drinking water regulations.

Self-poled molybdenum disulfide embedded polyvinylidene fluoride (MoS2@PVDF) hybrid nanocomposite films fabricated by a bar-printing process are demonstrated to improve the output performances of triboelectric nanogenerators (TENGs). Comparative analyses of MoS2@PVDF films with different MoS2 concentrations and the synergic effect based on postannealing at different temperatures were examined to increase the triboelectric open-circuit voltage and the short-circuit current (∼200 V and ∼11.8 μA, respectively). A further comprehensive study of the structural and electrical changes that occur on the surfaces of the proposed hybrid nanocomposite films revealed that both MoS2 incorporation into PVDF and postannealing can individually promote the formation of the β-crystal phase and generate polarity in the PVDF. In addition, MoS2, which provides triboelectric trap states, was found to play a significant role in improving the charge capture capacity of the nanocomposite film and increasing the potential difference between two electrodes of TENGs. The produced electrical energy of the developed wearable TENGs with excellent operational stability for a long duration was utilized to power a variety of mobile smart gadgets in addition to low-power electronic devices. We believe that this study can provide a simple and effective approach to improving the energy-harvesting capabilities of wearable TENGs based on hybrid nanocomposite films.

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A facile electrochemical sensing nanoplatform for detection of ultralow dopamine (DA) concentrations is developed through modification of cobalt-benzene tricarboxylic acid (Co-BTC) derived cobalt-carbon-matrix (Co-C-matrix). To enhance surface reactions and enzyme-like activities involved in interaction with DA, the structural integration of hybrid Co-C-matrix into Co-BTC as metal-organic framework is investigated, resulting in nanostructured transducing media with high sensitivity and selectivity as the catalyst. The Co-C-matrix nanoplatform exhibited the improved performance based on electrocatalytic oxidation of DA with high sensitivity of 7176 µA mM-1 cm-2 and low detection limit of 10 nM. Furthermore, the linearity of an amperometry peak toward DA concentration over a wide concentration range of 10-25 µM was observed under optimal conditions. Excellent selectivity in the presence of potential interferents and operational stability in ambient air for 30 days as well as under environmental conditions for the electrochemical oxidation of dopamine were achieved. The practical feasibility of these non-enzymatic biosensors is demonstrated on real samples, where DA is detected in human serum with outstanding recovery of up to 100%. The synergetic effect of Co atoms dispersed in the matrix of the carbon nanohybrid results in abundant active sites for DA oxidation and electron transfer pathways.