A Non-Enzymatic Electrochemical Biosensor for the Detection of Methylglyoxal in Human Blood Plasma

Methylglyoxal (MG) is one of the emerging biomarkers of diabetes, and the design and development of biosensors for it has gained a considerable benefit. At the same time, designing electrochemical MG biosensors with the working electrode modified with nanointerface and enzyme by drop casting has a number of disadvantages including fouling, nonuniform coating, and uncontrolled thickness. In this background, electrodeposited CS/MWCNTs on GCE for ultralow detection of MG has been proposed to minimise the limitations. The electrode was optimized for a range of scan rates and pH values in order to obtain the maximum response for a given concentration of MG. Cyclic voltammetry technique was employed to detect MG in human plasma. The reduction of MG to acetol at −0.745 V with a peak current of 291 $\mu \text{A}$ when 10 nM of MG was added to the NaCl electrolyte. The linearity range was observed from 10 to 40 nM with a detection limit (LOD) of 25 pM, a quantification limit (LOQ) of 85 pM and a response time of less than 10 s. The performance of the sensor was tested in the presence of blood plasma samples.