Poly (brilliant cresyl blue)-reduced graphene oxide modified activated GCE for nitrite detection: Analyzing the synergistic interactions through experimental and computational study

Abstract

In this article, theoretical and computational (CP) analysis were carried out on the experimental data for the nonenzymatic oxidation of nitrite at the modified electrode to better understand the underlying chemistry. We studied the kinetics of the electron transfer process through various electroanalytical techniques and simulated the cyclic voltammetry (CV) data using Butler-Volmer equation. The CP methods were used for understanding the molecular interaction processes at the electrode-electrolyte interface. The modified electrodes were developed by the electrodeposition of poly (brilliant cresyl blue) (PBCP) on an electrochemically reduced graphene oxide (ERGO) at the activated glassy carbon electrode (AGCE) (AGCE/ERGO/PBCB). The AGCE/ERGO/PBCB sensor was characterized through electrochemical and electron microscopy methods. Analysis of the characterization data supported our assumption, that AGCE is the better platform for the optimal electrochemical reduction of GO compared to the GCE for the purpose of the electropolymerization process. Simulated CV showed that the oxidation process followed a 2e− transfer pathway, but the electron transfer took place in a step wise manner. While, CP data revealed that the AGCE, ERGO, and PBCB interacted with each other through the parallel-displaced and sandwich types π – π stacking, and electrostatic interactions. H⋯O–H, and H⋯N–H hydrogen bonds between the functional groups of AGCE, and ERGO also promoted the electron transfer process. The AGCE/ERGO/PBCB was then used for the nonenzymatic detection of the nitrite species in the acidic medium using amperometric and CV techniques. The sensor was also tested for real sample analysis.