Development of ZnO nanoflowers-assisted DNAzyme-based electrochemical platform for invertase and glucose oxidase-dominated biosensing

Abstract

The investigation on invertase (INV) and glucose oxidase (GOx)-dominated biological process offers a new opportunity for the development of clinical diagnosis and prognostic treatment. Herein, a ZnO nanoflowers (ZnONFs)-assisted DNAzyme-based electrochemical platform for INV- and GOx-dominated biosensing is proposed by the change of pH in microenvironment. In this strategy, INV can usually catalyze the dissolution of sucrose to generate glucose, and glucose is then consumed by GOx to produce H₂O₂ and gluconic acid, in which ZnONFs can be effectively etched into free Zn²⁺ ions. Subsequently, the released Zn²⁺ ions have a shearing action for Zn²⁺-specific DNAzyme, thus triggering hybridization chain reaction along with the imbedding of methylene blue. The excellent electrochemical signals illustrate the method can be employed well for testing sucrose, INV and GOx with a low detection limit (0.019 μM, 0.047 mU/mL and 0.012 mU/mL, respectively). Finally, a series of basic and advanced logic gates (YES, AND, INHIBIT, and AND-AND-INHIBIT) in the biological process are constructed with different logic inputs, providing a valuable platform for the establishment of advanced molecular devices for bioanalysis and clinical diagnostics.

Keywords: DNAzyme; Electrochemical platform; Glucose oxidase; Invertase; Logic gate; ZnO nanoflowers.