Development of an enzyme-based biosensor for atrazine detection

Abstract

An amperometric biosensor for detection of the photosynthetic inhibiting herbicide atrazine is described. The sensor, incorporating the enzyme tyrosinase, was sensitive to a wide range of di- and triphenols. It displayed a fast response, with 95% of the steady-state current being obtained within 25 s, and had a half-life of 8 d but retained some activity for up to 20 d. This biosensor displayed a notable decrease in response in the presence of atrazine. Atrazine inhibition of the biosensor response was found to be reversible. The electrode construction consisted of tyrosinase cross-linked on a poly(pyrrole) coated gold electrode surface. The inhibition of enzyme activity in the presence of atrazine was measured amperometrically. Atrazine concentrations of 5 × 10^–6 mol dm^–3 were measured in a hydrodynamic cell and of 1 × 10^–5 mol dm^–3 in a flow-through system.