Sensitive Electrochemical Biosensor Using Gold and Manganese (IV) Oxide Nanomaterials on Multiwalled Carbon Nanotubes for the Determination of Homocysteine With a Portable Potentiostat

Serum homocysteine (Hcy) is considered to be a reliable biomarker of cardiovascular, cerebrovascular and neurological diseases. Therefore, rapid, specific and sensitive measurement of homocysteine is crucial for prevention and diagnosis. Electrochemical methods, which benefit from simplicity, low-cost and quick response, have been widely utilized in the determination of targeted biomolecules. In this work, based upon a portable mini-potentiostat, a homocysteine electrochemical biosensor has been successfully developed combined with the modification of gold and manganese (IV) nanomaterials on multiwalled carbon nanotubes (MWCNTs) (denoted as Au@MnO2/MWCNTs) on screen-printed electrodes (SPEs). Due to the excellent electrochemical activity and catalytic capability of Au@MnO2/MWCNTs, the proposed electrochemical biosensor exhibited wide-linear range (5-125 mu mol L-1), high sensitivity (0.01110 mu A (mu mol L-1)-1) and low detection limit (0.6173 mu mol L-1) for homocysteine, requiring only 400 s to complete detection. It was effectively applied in the determination of serum homocysteine, and the results were consistent with those of an automated clinical chemistry analyzer. Furthermore, the simple and portable electrochemical device offers a promising manner for on-site analysis and home health monitoring.