Voltammetric study of a detergent-stable Actinomadura keratinilytica lipase CPT29-cross-linked GA/BSA platinum biosensor Scientific paper

Abstract

This study describes the immobilization of a native lipase (LCPT29) from Actinomadura keratinilytica strain CPT29 isolated from poultry compost in the northeast of Algeria in order to detect ester pollutants in an aqueous environment. For this purpose, this detergent-stable lipase was immobilized with glutaraldehyde as a cross-linker, in the presence of bovine serum albumin (BSA) onto a platinum (Pt) electrode. The prepared enzyme membrane was charac­ter­ized by FT-IR spectroscopy, confirming its network formation, while its coating of the Pt-electrode was evaluated using cyclic voltammetry. The effectiveness of the cross-linked enzyme membrane-coated working electrode was evaluated electrochemically by detecting propyl 4-hydroxybenzoate (PHB) as a model analyte. Under optimal conditions and at an applied potential of –250 mV vs. Ag/AgCl, the LCPT29-based biosensor showed a linear response over the con­centration range from 10^-14 to 10^-8 mol L^-1 (r = 0.991), with a detection limit of 10-14 mol L^-1. The biosensor exhibited high sensitivity (0.0327 mA L mol^-1), good stability (RSD = 0.37 %) and significant selectivity as well as the ability to analyse trace amounts of PHB in real water samples, demonstrating its potential for electro­chemical biosensing applications.