基于酶催化银沉积质量放大的血吸虫压电免疫传感器的研究

Studies of a Novel Mass Amplification Piezoelectric Immunosensor for Schistosoma-Japonicum Antibody Based on Enzymatic Catalyzation Deposition of Silver

发展了一种基于酶催化金属银沉积信号放大的新型高灵敏气相压电免疫传感检测技术.先将血吸虫抗原(SjAg)共价固定在石英晶体表面,制备得到血吸虫压电免疫传感器.检测时,在晶振上滴加不同浓度的待测血吸虫抗体,再将碱性磷酸酶标记的二抗通过夹心方式结合到传感器表面.然后利用碱性磷酸酶催化磷酸化的抗坏血酸酯水解从而还原硝酸银,使金属银沉积在晶振表面上,放大传感器的质量响应信号.实验结果表明该传感检测方法可显著提高气相压电免疫传感器的检测灵敏度,传感器对血吸虫抗体的响应线性范围在1～225 ng/mL,检测下限为1 ng/mL.

A new mass amplification piezoelectric immunosensing method in gas phase was developed for the Schistosoma-Japonicum antibody（SjAb）,which is based on the enzymatic catalyzation deposition of silver.On the surfaces of quartz crystals with a resonant frequency of 9 MHz,a molecular antigen of Schis-tosoma Japonicum（SjAg） was covalently immobilized via a self-assembly membrane of 2-mercaptoethylamine.By exposing the crystals to the SjAb solution and the alkaline phosphatase（ALP） labeled second antibody solution in turn,the ALP was bounded to the quartz crystal surfaces by a ＂sand-which＂ format,and it was then used as a biocatalyst for the hydrolyzation of 2-phospho-L-ascorbic acid to form the reductive ascorbic acid and further to yield mental silver deposit on the surfaces of quartz crystals,resulting in an amplified mass sensing effect.The sensing method is quite simple and sensitive,and the SjAb can be linearly determined in the range of 1～225 ng/mL,and the detection limit reaches as low as 1 ng/mL.