Synthesis and synergistic effect of positively charged jute carbon supported AuNPs coated polymer nanocomposite for selective determination of nitrite

[Display omitted] •Synthesis of positively charged nanocomposite (AuNPs-PMTC-JC).•Modification of GCE with the nanocomposite for NO2− ion detection.•Discussing the possible reaction mechanism and kinetics of NO2− ion oxidation.•Determining a wide linear range (0.4 µM −1 mM) with LOD value of 0.16 µM.•Evaluating the selectivity and practical applicability of the modified electrode. A nanocomposite with highly dispersed AuNPs coated poly[2-(methacryloyloxy) ethyl] trimethylammonium chloride (PMTC) supported upon jute carbon (AuNPs-PMTC-JC) was prepared in aqueous medium for the selective determination of nitrite (NO2−) ions. Quaternary ammonium groups of PMTC in the nanocomposite results in a positive zeta potential, elevating the electrocatalytic properties of the modified electrode for negatively charged NO2− ions oxidation. The AuNPs-PMTC-JC composite was characterized using UV–vis, FESEM, TEM, SAED, XRD, EDS, CV and EIS. The LOD (S/N = 3) value for NO2− determination is 0.16 µM in the linear range of 0.4–706.5 µM based on the i-t current response, while it is 1.28 µM based on CV responses in the wide range of 10–1000 µM. The modified electrode is highly selective for NO2− ions and shows highly stable, and reproducible results. CV was used to analyze tap water spiked with NO2− and a recovery close to 100 % was observed.