Visualization analysis of glucose, lactate and cholesterol based on an electrochemiluminescent biosensor array

In this work, three specialized oxidases for glucose, lactate and cholesterol are absorbed on carbon microspheres (CSs), which can produce hydrogen peroxide during their substrate-specific enzymatic activity. Electrochemiluminescent (ECL) is generated by the electrochemical reaction between luminol and hydrogen peroxide on an ECL biosensor array, whose light signals are collected by a CCD camera. Under optimum conditions, calibration curves are constructed for glucose, lactate, cholesterol concentrations and ECL intensities. The detection limits of the different biosensors are found to be 12 μM for glucose, 3 μM for lactate and 19 μM for cholesterol. Furthermore, the resulting ECL biosensor array is expected to be an alternative analytical tool in clinical analysis because of its good stability, acceptable precision and reproducibility.