A novel cascade catalytic electrochemical biosensor based on bifunctional Mn3O4@AuNPs with self-supplied O2 property and glucose oxidase-like activity for ultrasensitive detection of microRNA

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-01, Vol.479, p.147627, Article 147627
• Main Authors: Kong, Lingqi, Li, Hao, Xu, Shuang, Xia, Mao, Han, Zeshuai, Zhuo, Ying, Chai, Yaqin, Tan, Xingrong, Yuan, Ruo
• Format: Article
• Language: English
• Subjects: DNAzyme; Electrochemical biosensor; miRNA-499; Mn3O4@AuNPs
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.147627

The Mn3O4@AuNPs with glucose oxidase-like activity and self-supplied O2 property could not only catalyze the oxidation of glucose to gluconic acid and the reduction of dissolved O2 to low concentrations of H2O2 in the presence of hemin/G-quadruplex DNAzyme with peroxidase-like activity, but also electrocatalyze water splitting to produce more dissolved O2 and further assist in the production of high concentration of H2O2, resulting in an incremental enzyme cascade catalytic efficiency for a markedly improved electrochemical signal. [Display omitted] •The Mn3O4@AuNPs have glucose oxidase-like activity and self-supplied O2 property.•The Mn3O4@AuNPs could electrocatalyze water splitting to produce more dissolved O2.•Enzyme cascade efficiency was markedly improved due to high concentrations of H2O2.•Dual Mg2+-assisted DNAzyme cleavage recycle increased target conversion efficiency.•The electrochemical biosensor achieved the ultrasensitive detection of miRNA-499. Herein, a bifunctional nanomaterial Mn3O4@AuNPs with self-supplied oxygen (O2) property and glucose oxidase-like activity was exploited to construct a novel cascade catalytic electrochemical biosensor for ultrasensitive detection of microRNA-499 (miRNA-499). Impressively, compared with the traditional AuNPs nanozyme with single glucose oxidase-like activity, the Mn3O4@AuNPs could not only act as a glucose oxidative mimetic enzyme to catalyze the oxidation of glucose to gluconic acid and the reduction of dissolved O2 to low concentration of hydrogen peroxide (H2O2) to obtain a electrochemical signal in the presence of hemin/G-quadruplex DNAzyme with peroxidase-like activity, but also electrocatalyze water splitting to obtain abundant dissolved O2 to further assist in the production of high concentration of H2O2 for a significantly improved electrochemical response. Meanwhile, with the aid of the target-induced dual Mg2+-assisted DNAzyme cleavage recycling amplification for the increasement of target miRNA-499 conversion efficiency, the proposed electrochemical biosensor achieved the ultrasensitive detection of miRNA-499 with a detection limit as low as 6.2 aM. As a result, this strategy might provide a potential method to upgrade the catalytic efficiency of mimic enzyme cascade reaction with eventual applications in bioanalysis and disease diagnosis.