Application of an enzyme encapsulated metal-organic framework composite for convenient sensing and degradation of methyl parathion

Abstract

Terbium-BTC (BTC = 1,2,4-Benzenetricarboxylic acid) metal-organic framework (MOF) has been employed for in-situ encapsulation of hexahistidine-tagged organophosphate hydrolase (OPH6His) enzyme. The enzymatic activity and stability of OPH6His were found remarkably enhanced after its encapsulation within the MOF. The potential of this enzyme-MOF composite (OPH6His@Tb-BTC) has been explored as a dual platform to simultaneously detect organophosphate pesticides (OPPs) and catalyze their degradation. The OPH6His@Tb-BTC exhibited improved enzymatic activity (by approximately 30%) and reusability (at least five cycles). It is demonstrated to be a highly sensitive and simple optical bioprobe for the detection of an OPP candidate, methyl parathion with a low limit of detection (2.6 nM). A less toxic metabolite was formed through catalytic conversion of methyl parathion (i.e., upon its incubation with OPH6His@Tb-BTC), further supporting the promising role of this composite in the remediation of pesticide-contaminated environments.