Reagentless and regenerable immunosensor for monitoring of immunoglobulin G based on non-separation immunoassay.
Based on the enhancement of fluorescein isothiocyanate (FITC) fluorescence caused by reactions between proteins, we developed a reagentless, regenerable and rapid immunosensing system to determine immunoglobulin G (IgG). Fluorescence intensity of the immobilized FITC depends on IgG concentration, ranging from 10 to 50 microg/ml, specifically, even with co-existing proteins. The response time is 30 min during steady-state measurement and is less than a minute during transient measurement. When the FITC-labeled protein A binds to IgG, the surrounding atmosphere of FITC becomes hydrophobic. Since the fluorescence intensity of fluorescent substances generally increases at a hydrophobic environment, FITC fluorescence intensity increases with the concentration of protein A bonding to IgG. This system is regenerable because the fluorescence enhancement repeatedly occurs every time the immobilized fluorescent reagent is immersed in sample solutions.
Aoyagi
Satoka
S
Faculty of Engineering, Department of Applied Physics, Seikei University, 3-3-1 Kitamachi, Kichijoji, Musashino-shi, 180-8633, Tokyo, Japan. aoyagi@apm.seikei.ac.jp
Imai
Rika
R
Sakai
Kiyotaka
K
Kudo
Masahiro
M
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017743:Equipment Reuse; D016650:Fluorescein-5-isothiocyanate; D005470:Fluorometry / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D007202:Indicators and Reagents; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013205:Staphylococcal Protein A / Q000276:immunology; D014159:Transducers
D020099:Coated Materials, Biocompatible; D007074:Immunoglobulin G; D007202:Indicators and Reagents; D013205:Staphylococcal Protein A; D016650:Fluorescein-5-isothiocyanate