Catalytic and Electrochemical Sensing Studies of Silver/Poly(1-Naphthylamine) Nanocomposites Synthesised by a Green Method

Metal nanoparticles incorporated conducting polymer nanocomposites have outstanding properties and potential applications in various fields and significant research has been carried out over the last two decades for the development of efficient methods for their synthesis. The current study describes a microwave-assisted, rapid, and environmentally friendly method for depositing silver nanoparticles (AgNPs) over poly(1-naphthylamine) (PNA) using clammy cherry (Cordia Obliqua willd) extract as a reductant to create silver/nanocomposites (Gr-Ag/PNA) with varying silver contents. Thermal stability and charge transfer kinetics of PNA was significantly improved upon introducing AgNPs, as evidenced by the thermogravimetric analysis and electrochemical investigations, respectively. All prepared Gr-Ag/PNA nanocomposites could show improved catalytic activity towards the borohydride-aided reduction of 4-nitrophenol (4-NP) and the pseudo-first-order rate constants showed a direct relationship with the percent of silver incorporated over PNA. Additionally, for the first time, the Gr-Ag/PNA modified carbon paste electrode (Gr-Ag/PNA/CPE) was utilized to validate its usefulness and applicability in the electrocatalytic reduction of 4-NP. A low-cost enzymeless voltammetric 4-NP sensor based on Gr-Ag/PNA/CPE was fabricated and it showed excellent selectivity for 4-NP, as well as a strong linear response over a wide range of 4-NP concentrations (30-1000 𝜇M) and a detection limit of 6.25 𝜇M.