Boronate based surface plasmon resonance sensors for determination of glycosylated protein

Blood glucose and glycosylated hemoglobin (HbA1c) measurements are the most commonly used tests for diagnosing diabetics. Measurement of blood glucose is an indicator of daily glycemic status. HbA1c measurement is an indicator of the risk of and diabetes to develop. Glycosylated hemoglobin (HbA1c) is the result of glucose binding of the β-chain of hemoglobin to N-terminal valine and reflects the average glucose value over the past 2-3 months. HbA1c in the blood concentration of more than 141mg / dL is often enough to diagnose diabetes. Boronic acid derivatives are often used in HbA1c determination due to the carbohydrate relationship based on the cis-diol interaction and determinations based on this association are mostly carried out by enzymatic sensors and HPLC. In addition to these methods, sensor studies have also started to be developed as an alternative. In this study it was aimed to determine HbA1c by a surface plasmon resonance sensor modified with a boronic acid derivative vinyl phenyl boronic acid. In the study, it was shown that the pH value is an important parameter for binding and the signal received is increased as the concentration is increased. Even at 10 μg/mL low concentration, signal can be received and showed that at clinical values more accurate measurement can be made. In artificial plasma studies, different sensograms were obtained for human serum albumin, IgG, and hemoglobin molecules which all could bind to modified chip and the selectivity to the molecules are distinctively differentiated in comparison with HbA1c. In the re-usability tests, the diffraction value varies considerably low, indicating that low cost is also suitable for targeted studies. The results also demonstrate that a SPR biosensor can be used as a precision technique to increase accuracy of HbA1c measurement.