| Info. | Vol.1 - No.1 (2007.03.20) |
|---|---|
| Title | Evaluation of Signal Stability from Electrochemical Immunoanalysis Based on the Enzyme ‘back-filling’ Immobilization to Biorecognition Interfaces |
| Authors | Jun Hwang Lee1, Byoung Yeon Won1& Hyun C. Yoon1 |
| Institutions | 1Department of Molecular Science & Technology, Ajou University, Suwon 443-749, Korea Correspondence and requests for materials should be addressed to H.C. Yoon (hcyoon@ajou.ac.kr) |
| Abstract | The signal stability from electrochemical immunosensors based on the enzymatic back-filling strategy was investigated. The presence of an analyte, especially antibody, which is bound to the surfaceimmobilized capture molecule, could cause a significant signal loss during subsequent handling procedures and signaling due to its limited affinity /stability. Compared to the typical method of detection, the signal from the back-filling immunoassay is generated differently from the covalently immobilized (?쁞ack-filled?? glucose oxidase (GOX) to the sensing surface, not from the bound analyte that is usually labeled with signaling molecules. Therefore, an enhancement of signal stability would be expected with the back-filling immunoassay. To evaluate the merits of the enzymatic back-filling method, various antibody dissociation conditions from immunosensor surfaces were compared in terms of signal stability and sensitivity. As a model immunosensing reaction, the 2, 4-dinitrophenyl (DNP) group was functionalized to the biorecognition surface on a thin-film gold electrode, and anti-DNP antibody was employed as the target analyte. Cyclic voltammetry was used for immunosensor signal registration and to trace the protein adsorption/dissociation process. The back-filling method was found to be suitable for the analysis of immune reactions without labeled-antibody molecules, and the signal stability was comparable to the affinity sensor employing biotin/avidin couple. |
| Keyword | Immunosensor, Electrochemistry, Back-filling, Dinitrophenyl, Glucose oxidase |
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