Homosistein-BSA-afinite temelli biyosensor tasarımı.

Objective: In this research, the detection and Reusability of Homocysteine by piezoelectric based Homocysteine Bioaffinity sensor using Quartz Crystal Microbalance (QCM) was aimed. Methods: The surface of silver sensor was subjected to a series of pretreatments. Surface activation process was done with the interaction of silver crystals with NaOH, acetone and methanol, respectively at definite times. Then, systeamine, glutaraldehyde attachments and BSA immobilization were performed to surfaces. BSA concentration was assayed within a range and the highest coupling BSA amount of 0.1 mg/mL was chosen as the most convenient concentration. Results: In the scope of BSA-Homocysteine affinity, the calibration graph of Homocysteine was formed after surface modification steps and the range of 0.5-2 μmol was estimated to give the best determination coefficient. Reusability of quartz crystals were tested by the cleavage of BSA-Homocysteine affinity in acidic and basic conditions. The NaOH solutions of 10-6, 10-3, 10-1, 1, 10 ve 100 mM (pH 8-9) were used to cleave the affinity and it was observed that no basic medium trials were convenient to reuse. Assays performed to break BSA-Homocysteine affinity in acidic condition were done with 0.01, 1, 10, 100 mM Glisin-HCl solutions of pH 2.5, 3.5, 5.5 and 6.5. The crystal reusability of 12 was reached with Glisin-HCl solution of 0.01, mM in pH 5.5. Conclusion: The highest reusability value of 30 repeat was reached when Glisin-HCl concentration is 1mM with pH 5.5 achieved to cleave BSA-Homocysteine affinity experiments. The experiments carried out in 10 mM Glisin-HCl acidic medium concentration gave oppurtunity to four reuse of silver crystal. [ABSTRACT FROM AUTHOR]