Fabrication of oxidase-like hollow MnCo2O4 nanofibers and their sensitive colorimetric detection of sulfite and l-cysteine

Abstract

Mixed transition-metal oxides (MTMOs) have attracted much research interest because of their promising applications in artificial enzymes. In this work, uniform hollow MnCo₂O₄ nanofibers have been fabricated via an electrospinning technique followed by a calcination process, which can be used as efficient oxidase mimics. In detail, the as-prepared hollow MnCo₂O₄ nanofibers display excellent oxidase-like activity toward the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) superior to their corresponding single-metal oxides without the addition of H₂O₂. Based on the high catalytic activity of hollow MnCo₂O₄ nanofibers and their inhibition effect by specific substances, the system of hollow MnCo₂O₄ nanofibers–TMB has potential to be applied in assays to detect sulfite and L-cysteine using a colorimetric approach with high sensitivity and selectivity. This work implies a broad application prospect of MTMOs in biosensors, environmental protection, food safety and medical science.