MIP-202 catalyst-integrated solid-contact potentiometric chloride sensor for versatile multiphasic detection of a sulfur mustard simulant

Abstract

Existing sensor devices for sulfur mustard (HD) detection are commonly bulky, sluggish in response, or not sensitive enough to detect HD contamination owing to its low aqueous solubility. Herein, we describe the development of a miniaturized catalytic electrochemical sensor, in both portable and wearable configurations, for the real-time, remote/on-site wireless detection of low micromolar levels of the HD simulant, 2-chloroethyl ethyl sulfide (CEES). The screen-printed CEES potentiometric sensor relies on coating a new solid-contact chloride ion-selective electrode (Cl-ISE) with a biomimetic zirconium metal-organic framework (Zr-MOF), MIP-202-based reagent layer for catalytic CEES hydrolysis and electrochemical detection of the liberated Cl anion. We describe and characterize the use of the green MIP-202 Zr-MOF towards such CEES hydrolysis, and demonstrate its superior catalytic performance versus the established MOF catalysts UiO-66 and HKUST-1 using proton nuclear magnetic resonance (1H NMR) analysis. The attractive analytical performance of the resulting strip and textile-based sensors has been demonstrated for the detection of CEES contamination in multiphasic samples ranging from aqueous buffered solutions, drinking water to aqueous buffered aerosols.