Application of Molecularly Imprinted Polymer for Determination of Glucose by Quartz Crystal Nanobalance Technique

Accurate determination of glucose is of great importance in various biotechnological processes, food industries, and diagnosing several metabolic disorders. To this point, many methods have been developed to meet this goal. Most of these methods are based on the enzymatic oxidation of glucose. However, the enzymes may be deactivated in different possible condition during storage and use. In this paper, a quartz crystal nanobalance (QCN) modified with a molecularly imprinted polymer (MIP) was developed for online monitoring of glucose in aqueous media without the use of enzymes. The MIP was synthesized by free radical polymerization using different functional monomers, including acrylamide, acrylic acid, allyl alcohol, and acrylonitrile. The findings indicate that acrylic acid has significantly better performance in terms of sensitivity and response time as compared with the other functional monomers. All measurements were performed in a flow cell. The frequency shifts due to the adsorption of glucose were found to be linear versus the concentration of glucose within the concentration range of 10-200 mg L^-1 with a correlation coefficient of R² = 0.9996. The sensitivity and lower limit of detection of the sensor were found to be 1.20 Hz/mg L^-1 and 4.4 mg L^-1, respectively. The results also indicate that organic compounds do not cause any significant interference with glucose determination by the MIPmodified QCN sensor, and using ion exchange resins can eliminate interference of ionic compounds.