Construction of electrocatalyst based on in-situ growth silver nanoparticles into hollow porous carbon spheres for hydrogen peroxide detection

One-step synthesis of nanosilver embedding laser-induced graphene for H2O2 sensor

During the novel coronavirus pandemic, hydrogen peroxide (H₂O₂) played an important role as a disinfectant. However, high concentrations of H₂O₂ can also cause damage to the skin and eyes. Therefore, the quantitative and qualitative detection of H₂O₂ is an important research direction. In this work, we report a one-step laser-induced synthesis of graphene doped with Ag NPs composites. It directly trims screen printed electrodes (SPE). Firstly, we did the timekeeping current method (CA) test on H₂O₂ using a conventional platinum sheet as the counter electrode, and obtained linear ranges of 1-110 μM and 110-800 μM with a sensitivity of 118.7 and 96.3 μAmM^-1cm^-2 and a low detection limit of (LOD) 0.24 μM and 0.31 μM. On this basis we have also achieved a good result in CA testing using Screen printed carbon electrodes (SPCE), laying the foundation for portable testing. The sensor has excellent interference immunity and high selectivity.

Highly efficient Ag doped δ-MnO2 decorated graphene: Comparison and application in electrochemical detection of H2O2

Cytotoxic H₂O₂ is an inevitable part of our life, even during this contemporary pandemic COVID-19. Personal protective equipment of the front line fighter against coronavirus could be sterilized easily by H₂O₂ for reuse. In this study, Ag doped δ-MnO₂ nanorods supported graphene nanocomposite (denoted as Ag@δ-MnO₂/G) was synthesized as a nonenzymatic electrochemical sensor for the sensitive detection of H₂O₂. The ternary nanocomposite has overcome the poor electrical conductivity of δ-MnO₂ and also the severe aggregation of Ag NPs. Furthermore, δ-MnO₂/G provided a rougher surface and large numbers of functional groups for doping more numbers of Ag atoms, which effectively modulate the electronic properties of the nanocomposite. As a result, electroactive surface area and electrical conductivity of Ag@δ-MnO₂/G increased remarkably as well as excellent catalytic activity observed towards H₂O₂ reduction. The modified glassy carbon electrode exhibited fast amperometric response time (<2 s) in H₂O₂ determination. The limit of detection was calculated as 68 nM in the broad linear range (0.005-90.64 mM) with high sensitivity of 104.43 µA mM^-1 cm^-2. No significant interference, long-term stability, excellent reproducibility, satisfactory repeatability, practical applicability towards food samples and wastewater proved the efficiency of the proposed sensor.