A novel molybdenum disulfide (MoS2)-biopolymer-coated screen-printed carbon electrode for rapid and simple detection of manganese ions in water

Abstract

Monitoring manganese ions (Mn²⁺) in drinking water is crucial for public health and water quality management. Mn²⁺ can cause discoloration, odor, or taste in tap water at concentrations above 0.05 mg L⁻¹ which is the U.S. Environmental Protection Agency's (EPA) secondary maximum contaminant level (SMCL). In this study, a novel molybdenum disulfide (MoS₂)-biopolymer-coated electrochemical electrode was developed for rapid and sensitive Mn²⁺ detection in water. The electrode, fabricated by electrodepositioning MoS₂ and chitosan onto screen-printed carbon electrode (SPCE), demonstrated a low detection limit of 1.03 μg L⁻¹ in 0.2 M acetate buffer solution (pH 4.5) using square wave adsorptive cathodic stripping voltammetry (SWAdCSV) with the optimized operational parameters: a deposition potential of +0.9 V, a deposition time of 300 s, an amplitude of 75 mV, and a frequency of 50 Hz. Simplified calibration curves were developed to reduce the need for frequent recalibrations, enabling practical applications in diverse water sources. Tests using real water samples achieved recoveries of 94–107 %, confirming the electrode's field applicability. This eco-friendly and cost-effective electrode provides a viable alternative to traditional laboratory-based spectrometric methods for Mn²⁺ monitoring, offering high sensitivity, portability, and potential widespread environmental applications.