Study On The Electrochemical Response Of S-BLM Modified With Cholesterol To Ss-DNA

Bilayer Lipid Membranes (BLMs), with the bilayer structure of biomembrance as well as good biological compatibility, is prone to be modified. BLMs can be endowed corresponding functions after embedding certain active molecules in BLMs. Cholesterol can adjust mobility of BLMs and enhance stability of BLMs. The proportion of cholesterol in BLMs plays important roles in biosensor based on supported BLMs. Thus, effects of different amount of cholesterol on stability of s-BLM were investigated. The dissertation advanced a novel formation method of s-BLM. By means of this new way we describes an electrochemical technique that exists the satisfying respond to single stranded deoxyribonucleic acids(ss-DNA) : thymidylic acid icosanucleotide(Oligo d(T20) ) based on surface stabilized s-BLM which is composed of egg phosphatidylcholine (PC). S-BLM modified with different amount of cholesterol and then their responses to ss-DNA were analyzed. We expected to establish biosensor system based on s-BLM integrated with ss-DNA. The main work and conclusions are as follows: (1) The stability influences of the different amount of cholesterol to s-BLM were studied. Influences of cholesterol to s-BLM were studied by comparing s-BLM modified with different amount cholesterol with Cyclic Voltammetry. The results indicated that s-BLM got the best stability of when the mol ratio of cholesterol and egg phosphatidylcholine is 1:1 in the BLM. (2) The responses of s-BLM to ss-DNA linked with tetrachloro-fluorescein (TET) were investigated. The responses of s-BLM to ss-DNA were observed in electrolyte solution with adding ss-DNA modified with TET. As a result,the response of s-BLM to ss-DNA turned up after 14 minutes. The peak current value appeared suddenly at first and then decreased gradually with leveled off in the end. (3) The responses of s-BLM to ss-DNA linked with pyrene were studied. Ss-DNA modified with pyrene was put into electrolyte solution and the responses of s-BLM to ss-DNA linked with pyrene were studied. The results showed the similar results to ss-DNA linked with TET. There were responses after 9 minutes. At first the peak current value suddenly come and then dropped gradually and finally with leveled off. Compared the responses of s-BLM to ss-DNA linked with TET to ss-DNA linked with pyrene, the response time of the former is shorter than the latter and the change extend of peak current value of the former is larger. In addition,the stability of s-BLM was improved greatly after modifying with ss-DNA. (4) The microarray biosensor based on s-BLM was built. The microarray biosensor model based on s-BLM was put forward. The microarray biosensor can examine multi-objects at the same time with combing micro-electron with micro-machining technology.