A recent study published in Sensors and Actuators: B. Chemical highlights the development of highly active oxidase mimics using MnO_x nanobelts (NBs) generated through laser irradiation in liquid techniques, this study was conducted by researchers from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences.

Although nanozymes with oxidase mimic activity have shown promise for biomarker sensing, their lower activity compared to natural enzymes has limited their wider application.

In this study, the researchers found that MnO_x NBs with an ultrathin layered structure improved catalytic active site exposure, and the negative charge layer of birnessite-type MnO_x NBs enhanced affinity for positive substrates such as 3,3',5,5'-tetramethylbenzidine (TMB).

Significantly, oxygen vacancies created by laser irradiation reduced the adsorption energy of the MnO_x NBs for oxygen, resulting in excellent substrate affinity (Km = 0.0087 mM) and high catalytic rate (Vmax = 6.04 × 10-7 M/s).

Furthermore, glutathione (GSH) inhibition of nanozymes with oxidase mimics was exploited to establish a rapid and highly sensitive method for GSH determination.

These findings may provide new strategies for the synthesis of highly active nanozymes for biomarker applications.

Growth mechanism of the ultrathin MnO_x NBs. (Image by JI Shihan)