Potentiometric Preparation And Application Of Marker Igg Immune Probes

A highly sensitive immunoprobe by means of covalent coupling of anti-immunologloblin G (anti-IgG) onto a Pt or a Ag electrode has been prepared and its potentiometric response to the immunoglobulin G (IgG) was investigated. The preparation of the immunoprobe is described as follows:1.the surface of the electrode was hydroxylated;2.3-aminopropyltriethoxysilane was covalently immobilized on the surface of the electrode;3.the anti-IgG was covalently linked with 3-aminopropyltri- ethoxysilane with the aid of glutaraldehyde.The prepared IgG immunoprobe was found to have a sensitively Nernst response to IgG because of the antigen-antibody reaction. The change of potential from beginning to end (the potentimetric difference, A? is made of quantifying parameter. The response of the immunoprobe to IgG is rapidly at normal temperature and can be repeatedly use after activation of regenerative reagent. The responses of the immunoprobe to IgG at different temperatures from 5 to 40 癈 were monitored. The temperature of the determination was controlled at 30 癈, because the response has the greatest and relatively stables value at 30 癈.The characteristics of the immunoprobes prepared by Pt and Ag electrode with different anti-IgG has been investigated in detailed, respectively.For the immunoprobe used Pt electrode, the response time of two immunoprobes prepared with rabbit anti-MIgG and rabbit anti-hlgG are 6 and 5 min, respectively. The calibration curve for MIgG and hlgG were obtained in the concentration range of 0.20 to1.20ng-mL"and 0.20 to 0.90 ng-mL"1 with the correlation coefficient of 0.9984 and 0.9977, respectively. The detection limit was estimated to be less than 0.20 ng-mL"'. The immunoprobe can be repeatedly used 8 times, if urea of 0.25 mol-L"' is as regenerative reagent.For the immunoprobe used Ag electrode, the response time of two immunoprobes prepared with rabbit anti-MlgG and rabbit anti-hlgG are all 5 min. The calibration curve for MlgG and hlgG were obtained in the concentration range of 0.20 to 1.40 ng mL"1 and 0.20 to 1.20 ng-mL"1 with the correlation coefficient of 0.9984 and 0.9993, respectively. The detection limit was estimated to be less than 0.10 ng-mL"1. The immunoprobe can be repeatedly used 4 times, if HC1 of pH 1.9 is as regenerative reagent.As a feasible test to application of the immunoprobe, the IgG contents of rabbit anti-mouse serum, rabbit anti-human serum and human serum were determined. To Pt electrode ,the obtained results showed that recoveryis 96%, 103%,95%;To Ag electrode ,the obtained results showed that recovery is 101% 98%, 106%.In conclusion, a highly sensitive immunoprobe that responds to IgG has been developed. The covalent immobilization of anti-IgG on the Pt and Ag electrode was found to be effective in producing high sensitiveity, stability and reproducibility. And this immunoprobe can conveniently apply to the determination of practical sample.