Piezoelectric immunosensor for detection of complement C6 Original Research Article

A highly sensitive piezoelectric immunosensor has been developed for the determination of complement C6. Anti-C6 antibody was immobilized onto the gold electrodes of a 9 MHz AT-cut piezoelectric crystal. The coated crystal with polyethyleneimine adhered to it combined with glutaraldehyde cross-linking to immobilize the antibody showed better results than the physical adsorption method with respect to sensitivity and reproducibility. Under the optimized experimental conditions, the sensor was successfully used for the determination of human complement C6 in the concentration range of 10−7–10−5 g/ml. Other proteins in human serum did not interfere with the determination remarkably. The crystal could be regenerated nearly 12 times, when bound materials on the crystal surface were eluted by strong acid and strong alkali solutions and subsequently cleaned in a ultrasonic cleaner.