Nanozymes “Artificial Peroxidase”: Enzyme Oxidase Mixtures for Single‐Step Fabrication of Advanced Electrochemical Biosensors

Abstract

We report the single-step fabrication of advanced electrochemical biosensors upon drop-casting of "artificial peroxidase", that is, oxidase-containing mixtures. Compared to bienzyme biosensors, we substitute peroxidase with more active and stable nanozymes based on catalytically synthesized Prussian Blue. The electroactivity of nanozymes in the sensing membrane was facilitated with carbon black nanoparticles, which resulted in record sensitivity of the H 2 O 2 transducer exceeding 1.1 A M À 1 • cm À 2. Both glucose and lactate oxidases were co-immobilized with nanozymes in alkoxysilane or perfluorosulfonated ionomer membranes. The proposed drop-casting approach results in biosensors that are advantageous over those conventionally produced upon layer-by-layer immobilization in terms of i) almost an order of magnitude increased sensitivity, ii) unsurpassed biosensor-to-transducer sensitivity ratio reaching the value of 0.3, and iii) three times extended operational lifetime.

Biosensor Based on Peroxidase-Mimetic Nanozyme and Lactate Oxidase for Accurate L-Lactate Analysis in Beverages

“…The first nanozyme was described back in 1970 by Breslow et al [ 16 ]. From that time, hundred different types, structures, and properties nanozymes were synthesized, characterized, and successfully used in sensor technology [ 17 , 18 , 19 , 20 ]. Despite the large number of lactate biosensors created on the basis of different nanocomposites, increasing their sensitivity and their adaptation for the analysis of the target analyte in complex mixtures of real samples is still an urgent task.…”

Core-Shell Iron-Nickel Hexacyanoferrate Nanoparticle-Based Sensors for Hydrogen Peroxide Scavenging Activity

“…In 2018 a new sensing material-Prussian Blue nanoparticles-was proposed by our research group [34]. PB nanoparticles can be prepared by chemical [34] or electrochemical [35] means and used to create improved sensors [36] and biosensors [37,38], whose performance characteristics are better compared to sensors based on Prussian Blue films. The only disadvantage of PB nanoparticles-low operational stability-was overcome in 2021 by performing catalytic synthesis on core-shell nanoparticles based on a PB core stabilized with a nickel hexacyanoferrate (NiHCF) shell [39].…”