Facile green microwave-assisted synthesis of silver-chitosan nanoparticle for antioxidant, antibacterial, and non-enzymatic biosensor for dopamine detection

The green synthesized nanoparticles have multiple functions because of their ecological origin and biocompatibility. The silver-chitosan nanoparticles (Ag-CS NPs) were synthesized using the microwave-assisted green synthesis method at different reaction temperatures of 80–120 °C. The Ag-CS NPs nanoparticles have spherical shapes, with an average particle size between 19 and 49 nm. The in vitro antioxidant potential of Ag-CS NPs was examined, and the obtained IC50 value was 36.94 µgml^−1. The antibacterial activity against Vibrio cholerae and Staphylococcus Aureus produced maximum inhibition zones of 11.1 mm and 9 mm, respectively. The biosensing ability of Ag-CS NPs for dopamine using differential pulse voltammetry (DPV) showed a LOD of 0.01 µM, with a linear range of 0.1–60 µM, which is less than 0.3–3 mM for detecting DA in urine samples. These findings demonstrate the potential of Ag-CS NPs as an inexpensive antioxidant and antibacterial agent. The proposed sensor was successfully applied to rapidly detect dopamine in human urine. Graphical abstract