Development of an immunosensor for human ferritin, a nonspecific tumor marker, based on surface plasmon resonance.
A direct human ferritin immunosensor was developed using anti-human ferritin monoclonal antibodies (MAbs) immobilized on the gold surface of a self-assembled surface plasmon resonance (SPR) apparatus. A kind of self-assembled monolayer (SAM) prepared by cystamine-glutaraldehyde method was applied to immobilize the MAbs. The reusability of the sensor chip adopting the SAM was found to be better than the other immobilization methods including adsorption, protein A, concanavalin A method. Ten cycles of measurements could be performed on the same chip regenerated with a 0.1M HCl solution. A linear relationship existed between the angle shifts (millidegrees) and the log values of ferritin concentrations in the range from 0.2 to 200 ng/ml in buffer and human serum. When used for 15 days, the angle shifts were all >95% of those on the response at the first day. A 10 M NaOH solution was used for clearing nonspecific binding in human serum. Correlation coefficient was 0.991 between this SPR method and chemiluminescent immunoassay for determination of ferritin in clinical human serum samples. The SPR sensor offers advantages of simplicity of immobilization, high sensitivity, high specificity, low sample requirement, high reusability, no label and no pretreatment etc.
Chou
Shu-Fen
SF
Department of Biotechnology, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan, ROC. chousf26@ms58.hinet.net
Hsu
Win-Lin
WL
Hwang
Jing-Min
JM
Chen
Chien-Yuan
CY
D000911:Antibodies, Monoclonal / Q000276:immunology; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques; D003627:Data Interpretation, Statistical; D005293:Ferritins / Q000032:analysis* / Q000737:chemistry; D008163:Luminescent Measurements; D020349:Surface Plasmon Resonance; D013997:Time Factors
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D005293:Ferritins