MoOx quantum dots with peroxidase-like activity on microfluidic paper-based analytical device for rapid colorimetric detection of H2O2 released from PC12 cells

Abstract

Diagnostic assays made of microfluidic paper-based analytical devices have become the focus of considerable attention in developing countries because of simplicity, low cost, user friendliness, and no requirement for complex equipment, which is suitable to point-of-care testing. Considering the intrinsic shortcomings of nature enzyme, synthesis of artificial peroxidase mimics possessing improved catalytic activities relative to native enzymes is of considerable interest for the development of highly sensitive and stable sensor. In this paper, water-soluble molybdenum oxide quantum dots (MoOx QDs) were developed as highly effective biomimetic catalysts which were prepared by a facile ultrasonic-assisted hydrothermal method. The resulted MoOx QDs displayed peroxidase-like activity with high sensitivity and specificity, and were constructed for efficient colorimetric quantitative detection of H2O2 based on microfluidic paper-based device. As low as 0.175 μmol/L H2O2 could be determined at a linear range from 1 to 20 μmol/L. Moreover, this biosensing device was successfully applied for visual detection of H2O2 released from PC12 cells with the advantages of low cost, rapid response and portability, indicating that the designed sensor of H2O2 has great potential in biotechnology and clinical diagnosis.