A promising electrochemical sensing platform based on a silver nanoparticles decorated copolymer for sensitive nitrite determination

Abstract

In this paper, we report a facile route to synthesize silver nanoparticles (Ag NPs) incorporated into a copolymer of methyl methacrylate (MMA) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) (abbreviated as P(MMA-co-AMPS)) and its application to construct an electrochemical nitrite (NO₂⁻) sensor. The copolymer nano-composite material (Ag–P(MMA-co-AMPS) is characterized by means of transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, UV-vis spectroscopy, X-ray powder diffraction methods, thermogravimetric analysis and electrochemical impedance spectroscopy. Further, Ag–P(MMA-co-AMPS) is used to prepare an electrochemical sensing platform (ESP) on a glassy carbon electrode (GC) surface. NO₂⁻ is electrocatalytically oxidized at the ESP (GC/Ag–P(MMA-co-AMPS), which leads to a sensitive determination of NO₂⁻. The oxidation current of NO₂⁻ is linear to its concentration in the range of 1.0–100 000.0 μM and the detection limit is found to be 0.2 μM with a sensitivity 104.6 μA mM⁻¹ cm⁻². The observed analytical parameters such as wide linear range, low detection limit, high sensitivity and short response time are comparable or superior to other previously reported NO₂⁻ sensors. Kinetic parameters are evaluated using cyclic voltammetry and chronoamperometry. Finally it is demonstrated that the proposed sensor can be used for the selective determination of NO₂⁻ present in water samples and the results are quite promising.