Development of Chemically Modified Electrode With Methylene Blue Anchored Onto Silica/Niobium for Sulfide Analysis

Abstract

Sulfide released in the environment, due to high toxicity, even at low concentrations, may lead to serious environmental and health impacts. Therefore, is mandatory to develop highly sensitive, practical and inexpensive methods for detecting sulfide. Some of these analytical approaches are based on the methylene blue (MB) reaction, which has been successfully used in modified electrodes (MEs) development. MB-MEs hold promise as tools for detecting this electroactive anion. This study developed and characterized silica-niobiummethylene blue (SNMB) MEs, and evaluated their performance in sulfide determination through chronoamperometric and voltammetric techniques, under different experimental conditions. Within optimum conditions, the SNMB-MEs exhibited a linear response to sulfide anions from 7.6 to 63.4 μM, (r = 0.9979), whereas the detection and quantification limits were 2.03 mM and 6.77 mM, respectively. These results confirm the potential applicability of SNMB-ME for sulfide analysis and monitoring.