Enhancing Sensitivity of Manganese Detection in Drinking Water Using Nanomaterial AuNPs/GP

Abstract

Manganese (Mn) was previously considered a mere aesthetic concern that causes colored water and stained surfaces; however, recent epidemiological research found that excessive exposure to Mn has neurotoxic effects on humans, especially in children. In response to the health concerns, Health Canada and the World Health Organization moved towards stricter standards on Mn to protect public health. Currently, the standard analytical methods for Mn ^2+ are spectroscopic. Although they are highly sensitive, they are not cost effective or portable for high frequency analysis in the field. In this article, the sensitivity of electrochemical techniques, chronoamperometry (CA) and cathodic stripping voltammetry (CSV), are compared as well as the sensitivity of a non-modified glassy carbon screen-printed electrode (GCE SPE) vs a gold nanoparticle modified graphene (AuNPs/GP) coated GCE SPE for Mn ^2+ detection and quantification. Regarding the coating of the GCE SPE, detection performed with AuNPs/GP modified GCE SPE shows a wider linear range from 0–520 μ M and an improved LOD of 0.75 μ M. Application of the sensors was tested using drinking water samples returning high recovery rates from 92.9 to 106.8% depending on material and method used for Mn ^2+ detection and quantification.