The Researches On A Pyruvic Acid Biosensor Based On Modification Of Ferrocene And β-cyclodextrin

For determination of pyruvic acid, we used the ferrocene as an electron transfer mediator and pyruvate oxidase as a catalyzer, and had a systemic research for the immobilization of ferrocene and enzyme on the gold electrode. At last, a pyruvic acid biosensor with good stability and activity of electrochemistry and biocatalysis was constructed.There are two aspects of contents in the paper.The first step, we had an in-depth research for the immobilization of ferrocene on the gold electrode, and fabricated a modified gold electrode by glutaric dialdehyde cross-linked egg white as the matrix of ferrocene immobilization. This ferrocene electrode also has good stability and activity of electrochemistry.And the second step, we used glutaric dialdehyde cross-linkedβ-cyclodextrin as matrix of enzyme immobilization, a pyruvic acid biosensor based on the gold electrode was constructed. Due to the excellent electron transference of ferrocene, the microenvironment fromβ-cyclodextrin, and the inclusion complexation between ferrocene andβ-cyclodextrin, the biosensor has the good properties. The linear response lower limiting decreased to 3.33×10^-6mol/L, the relative standard deviation (RSD) is 2.58 % for six times of detection. Because pyruvic acid is the product of enzymatic reaction of glutamic-pyruvic transaminase(GPT), the biosensor is in prospect to be used into clinical occasion.