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In this research, we report an enhanced sensing response ethanol gas sensing device based on a ternary nanocomposite of molybdenum diselenide-zinc oxide heterojunctions decorated rGO (MoSe2/ZnO/rGO) at room temperature. The sensing performance of the ternary nanocomposite sensing device has been analysed for various concentrations of ethanol gas (1–500 ppm). The gas-sensing results have revealed that for 500 ppm ethanol gas concentration, the sensing device has exhibited an enhanced response value ( R g / R a ) of 50.2. Significantly, the sensing device has displayed a quick response and recovery time of 6.2 and 12.9 s respectively. In addition to this, the sensing device has shown a great prospect for long-term detection of ethanol gas (45 days). The sensing device has demonstrated the ability to detect ethanol at remarkably low concentrations of 1 ppm. The enhanced sensing performance of the ternary nanocomposite sensing device has highlighted the effective synergistic effect between MoSe2 nanosheets, ZnO nanorods, and rGO nanosheets. This has been attributed to the formation of two heterojunctions in the ternary nanocomposite sensor: a p-n heterojunction between MoSe2 and ZnO and a p-p heterojunction between MoSe2 and rGO. The analysis of the results has suggested that the proposed MoSe2/ZnO/rGO nanocomposite sensing device could be considered a promising candidate for the real-time detection of ethanol gas. [ABSTRACT FROM AUTHOR]

Detection of ethanol gas quickly and efficiently at room temperature is crucial for ensuring environmental, human as well as industrial safety. In this work, we have demonstrated a chemiresistive room temperature ethanol gas sensor based on vertically aligned tin sulfide (SnS) nanoplates. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) analysis have revealed the formation of orthorhombic, vertically aligned SnS nanoplates with high specific surface area. The sensor has been fabricated by depositing the SnS powder sample on ITO sheets using electrophoretic deposition (EPD), followed by the deposition of silver (Ag) electrodes using the thermal evaporation technique. The sensor obtained has exhibited a response value (R g/ R a) of 17.4–400 ppm ethanol gas concentration, a quick response, and a recovery time of 12.4 s and 20.2 s at room temperature. The sensor has demonstrated long-term stability of 15 min, impressive selectivity, and remarkable repeatability across three successive test cycles of ethanol gas at 400 ppm. Based on the experimental sensing results, a plausible mechanism has been proposed for the sensor. The sensing response of SnS-based sensor at room temperature expands its potential for innovative applications across industries, marking a significant advancement in sensing technology. [ABSTRACT FROM AUTHOR]

To address the issue of the lack of stable immobilization of antibodies on the biosensing matrix for repeated cycles of measurement, MoS2 biofunctionalized with chitosan (CS) is prepared to serve as a biosensing matrix. The electrochemical performance of the CS/MoS2 matrix towards the detection of neuron-specific enolase (NSE), a lung cancer biomarker, is also investigated. Unlike other complex matrices involving various steps of modification, the matrix studied herein involves only 2 steps of modification without the use of any label, amplifying its appeal for biosensing applications. The fabricated immunoelectrode is found to exhibit remarkable cyclic stability, with a sensitivity of 3.35 µA ng-1 mL cm-2 and a wide linear detection range of 0.1--100 ng mL-1. Also, the sensor is found to be fast, specific, reproducible, regenerable up to 4 cycles, and has a shelf life of 6 weeks. The stability study of our fabricated immunoelectrode revealed that the cumulative effect of CS and MoS2 ensures the stable immobilization of biomolecules on the immunoelectrode for 50 cyclic voltammetry (CV) cycles. The results of this study suggest that the proposed matrix will be promising in the fabrication of devices for early monitoring of protein biomarkers. [ABSTRACT FROM AUTHOR]