In Situ Growth of Silver Nanoparticles on Graphene Oxide Towards Electrochemical Nitrite Detection

Abstract Nitrite is a significant environmental pollutant present in industrial waste water, food additives, detergents, and physiological systems. Therefore, an effective electrochemical sensor is essential for nitrite determination. Accordingly in this work, graphene oxide (GO) is functionalized with 3‐aminopropyltrimethoxysilane (GO‐APTMS) and 3‐mercaptopropyltrimehtoxysilane (GO‐MPTS). Further, Silver nanoparticles (AgNPs) were grown on GO‐MPTS (GO‐MPTS/AgNPs) and GO‐APTMS (GO‐APTMS/AgNPs). GO‐APTMS/AgNPs and GO‐MPTS/AgNPs are characterized by different spectroscopic and microscopic techniques such as Fourier transform infrared (FT‐IR), UV‐vis and powder X‐ray diffraction(p‐XRD), transmission electron microscopy(TEM) with selected area electron diffraction (SAED) and energy dispersive X‐ray analysis (EDAX). The nanocomposites, GO‐APTMS/AgNPs and GO‐MPTS/AgNPs are immobilized on glassy carbon (GC) electrode and abbreviated as GC/GO‐APTMS/AgNPs and GC/GO‐MPTS/AgNPs, respectively. It exhibits excellent electrocatalytic activity toward the oxidation of NO 2 − . It shows the broad calibration range from 0.1 μM to 1 mM. The detection limit for NO 2 − is 90 nM and 80 nM for GC/GO‐APTMS/AgNPs and GC/GO‐MPTS/AgNPs, respectively. GC/GO‐APTMS/AgNPs and GC/GO‐MPTS/AgNPs exhibit sensitivity of 0.26 μA μM −1 cm −2 and 0.46 μA μM −1 cm −2 , respectively for NO 2 − determination. The modified electrode, GC/GO‐APTMS/AgNPs and GC/GO‐MPTS/AgNPs exhibit a wide calibration range, low detection limit, high sensitivity, selectivity, and stability for NO 2 − determination. Real sample analysis of tomato ketchup was performed at GC/GO‐APTMS/AgNPs and GC/GO‐MPTS/AgNPs with reliable recovery.