Modern Clinical Medicine Research

11

Authors: Nikita Ronzhin, Alexey Baron, Alexey Puzyr, Irina Baron, Andrey Burov, Vladimir Bondar

The study demonstrates the application of detonation nanodiamonds in designing testsystems for determination of physiologically important blood substances. One (urease), two (glucose oxidase and peroxidase) and three (cholesterol esterase, cholesterol oxidase and peroxide) enzymes have been covalently immobilized onto the surface of modified nanodiamonds (MND) to develop testsystems for biochemical detection of urea, glucose, and total cholesterol, respectively. In all cases, the immobilized enzymes exhibit functional activity and catalyze the formation of a colored product in the presence of the analyte. It has been found that the obtained MND-enzyme(s) complexes effectively function in deionized water and different buffers providing a linear output of the final product over a wide range of temperatures, pH and analyte concentrations. The model biosensors were found to be suitable for repeated use and retain most of their activity after storage at 4 °C in deionized water for two months. Practical applicability of the glucose and total cholesterol biosensors is demonstrated in human serum samples.