Cost-Effective Cholesterol Monitoring by Enzyme-Based Electrochemical Assay

Herein we present a practical, disposable, enzyme-based electrochemical biosensor to revolutionize a rapid and precise measurement of cholesterol level in saliva. To create a biosensor that can measure cholesterol levels, cholesterol oxidase (ChOx) was immobilized on disposable pencil graphite electrode (PGE) via EDC/NHS chemistry. This ChOx-PGE biosensor has been characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS). Various critical experimental parameters, including nafion concentration, enzyme concentration, enzyme-cholesterol interaction time, were optimized ensuring consistency and precision in our results and maintained constant throughout the experiments. Under optimum conditions, the detection limit was found to be 62 mu M and the sensitivity of the sensor was calculated as 1112.8 Ohm mM-1 cm-2. The potential interferences such as glucose, ascorbic acid, uric acid, cysteine was selected to test the selectivity and no significant response was observed. Finally, the proposed biosensor was effectively employed to measure cholesterol level in saliva. This biosensor boasts a rapid response time of just 20 minutes and achieves a remarkable detection limit of 95 mu M for salivary cholesterol, surpassing existing techniques. Our assay not only offers an innovative solution for cholesterol monitoring but also opens new horizons in point-of-care diagnostics with its disposable and practical design. We report a practical, disposable, enzyme-based electrochemical assay for measuring salivary cholesterol levels. Electrochemical impedance spectroscopy is used for the sensing of cholesterol after its interaction with cholesterol oxidase onto PGE surface. The proposed biosensor ensures a rapid response time (20-minute) and low detection limit (95 mu M). This approach promises a practical, point-of-care diagnostic solution for cholesterol monitoring.image