Amperometric detection of triclosan with screen-printed carbon nanotube electrodes modified with Guinea Grass (Panicum maximum) peroxidase

Abstract

Triclosan is a compound with antimicrobial activity broadly used in consumer products. Because of its well-documented toxicity, the amount of triclosan present in different products needs to be tightly controlled. This paper outlines a new amperometric sensor for triclosan detection consisting of a screen-printed carbon nanotube electrode (SPCNE) modified with Guinea grass peroxidase (GGP). The GGP-modified SPCNE was able to detect an enhanced electrochemical response of triclosan, unlike the bare SPCNE. The cyclic voltammograms of the GGP-modified SPCNE in a solution of potassium ferrocyanide showed an increase in the current values and linearity between scan rates and oxidation peak currents, suggesting a surface-controlled process. The GGP-modified SPCNE showed an excellent electrocatalytic activity to triclosan oxidation, at a redox potential of 370 mV, in the presence of hydrogen peroxide, exhibiting a linear response between 20 mM to 80 mM and a detection limit of 3 µM. This new amperometry system, based on carbon nanotubes integrated with GGP, becomes a potential tool for environmental analysis and food quality control.

Keywords

• amperometric biosensor; carbon nanotubes; guinea grass peroxidase; screen printed electrodes; triclosan.