Piezoelectric immunosensor for detection of complement C-6

A highly sensitive piezoelectric immunosensor has been developed for the de termination of complement Cg. Anti-Cg antibody was immobilized onto the gol d electrodes of a 9MHz AT-cut piezoelectric crystal. The coated crystal wit h polyethyleneimine adhered to it combined with glutaraldehyde cross-linkin g to immobilize the antibody showed better results than the physical adsorp tion method with respect to sensitivity and reproducibility. Under the opti mized experimental conditions, the sensor was successfully used for the det ermination of human complement Cg in the concentration range of 10(-7)-10(- 5) g/ml. Other proteins in human serum did not interfere with the determina tion remarkably. The crystal could be regenerated nearly 12 times, when bou nd materials on the crystal surface were eluted by strong acid and strong a lkali solutions and subsequently cleaned in a ultrasonic cleaner. (C) 2000 Elsevier Science B.V. All rights reserved.