Proton-Regulated Catalytic Activity of Nanozymes for Dual-Modal Bioassay of Urease Activity

Abstract

Benefiting from the merits of high stability and superior activity, nanozymes are recognized as promising alternatives to natural enzymes. Despite the great leaps in the field of therapy and colorimetric sensing, the development of highly sensitive nanozyme-involved photoelectrochemical (PEC) biosensors is still in its infancy. Specifically, the investigation of multifunctional nanozymes facilitating different catalytic reactions remains largely unexplored due to the difficulty in synergistically amplifying the PEC signals. In this work, mesoporous trimetallic AuPtPd nanospheres were synthesized with both efficient oxidase and peroxidase-like activities, which can synergistically catalyze the oxidation of 4-chloro-1-naphthol to produce benzo-4-chlorohexadienone precipitation on the surface of photoactive materials, and thus lead to the decreased photocurrent as well as increased charge-transfer resistance. Inspired by the proton-dependent catalytic activity of nanozymes, a self-regulated dual-modal PEC and electrochemical bioassay of urease activity was innovatively established by in situ regulating the activity of AuPtPd nanozymes through urease-mediated proton-consuming enzymatic reactions, which can remarkably improve the accuracy of the assay. Meanwhile, the determination of urease activity in spiked human saliva samples was successfully realized, indicating the reliability of the biosensor and its application prospects in clinical diagnosis.

Novel Ti3C2Tx MXene nanozyme with manageable catalytic activity and application to electrochemical biosensor

“…Nevertheless, natural enzymes are general cost to manufacture and store, unstable to transfer or modify, and sensitive to harsh physiochemical conditions. Nanozymes, nanomaterials with enzyme-like catalytic activities, well overcome the shortages of natural enzymes [8,9]. Therefore, nanozymes are attracting increasing attention in bioanalysis to substitute conventional natural enzyme [10,11].…”

Recent Advances on Nanozyme‐based Electrochemical Biosensors

“…Zhu et al . demonstrated that the peroxidase‐ and oxidase‐like activities of trimetallic AuPtPd nanospheres could be regulated by urease‐mediated proton‐consuming enzymatic reactions [100]. Based on this principle, a self‐regulated electrochemical bioassay for urease activity was developed and urease activity in spiked human saliva samples was successfully detected.…”

“…In addition to immunosensors, other electrochemical detection strategies were also developed for protein detection ( e. g ., uracil‐DNA glycosylase, matrix metalloproteinase 2, urease, glycated albumin, and telomeres) [98–102]. Zhu et al .…”

Nucleic acid isothermal amplification-based soft nanoarchitectonics as an emerging electrochemical biosensing platform

“…This is advantageous when compared to the above-mentioned ratiometric strategies that also showed two readouts, however, the two readouts are from the same detecting method. For example, electrochemical/ECL dual- mode, 138,139 electrochemical/photoelectrochemical (PET) dualmode, 140,141 and ECL/PET dual-mode 142 sensing strategies have been reported for improved cross-validating detection. Zhou et al combined the electrochemistry method and surface-enhanced Raman scattering (SERS) technology to realize a dual-mode assay for miRNA.…”