Potentiometric enzyme biosensor for rapid determination of formaldehyde based on succinimide-functionalized polyacrylate ion-selective membrane

Abstract A membrane-based potentiometric biosensor has been fabricated from poly(n-butyl acrylate-co-N-acryloxysuccinimide as both enzyme supporting matrix and pH-sensitive transducer on the Ag/AgCl screen-printed electrode for rapid and facile determination of formaldehyde. Detection of formaldehyde was based on H+ ion transfer reaction at the electrode–electrolyte interface facilitated with immobilized hydrogen ionophore via ion-ionophore complexation at the interface. The potentiometric enzyme biosensor demonstrated a broad linear range to formaldehyde from 0.5 to 220.0 mM (R2 = 0.9982) with fast response time within 8 s and sensitivity of 59.23 ± 0.85 mV/decade (n = 5). The operational stability of the formaldehyde biosensor with covalently immobilized alcohol oxidase showed > 95% sensitivity throughout the biosensor lifetime experimental period of 80 days. The formaldehyde biosensor based on succinimide-functionalized polyacrylate ion-selective membrane sustained negligible interference of potential interferants, e.g. methanol, ethanol, glucose and glycerol, and its feasibility for accurate assay of formaldehyde in commercial fish samples has been validated with UV–Vis spectrophotometric Nash standard method.