Open sandwich-based immuno-transistor for label-free and noncompetitive detection of low molecular weight antigen.
In this study, we proposed a new detection method, open sandwich-based immuno-field effect transistor (OS-FET) for label-free and noncompetitive detection of low molecular weight antigen. The principle of OS-FET is based on the detection of intrinsic molecular charges caused by the small antigen-dependent interchain interaction of separated V(L) and V(H) chains from a single antibody variable region using the field effect. Introducing V(H) chain and small antigen bisphenol A into the OS-FET with the immobilized V(L) chain on the gate, we could detect electrically and directly the binding of bisphenol A by V(H) and V(L) chains. Although the detection limit of OS-FET was 1 nM to detect bisphenol A for the standard deviation of control signal, the addition of isothiocyanobenzyl-EDTA with negative charges to the V(L) chain enhanced the detection limit to 1 pM. We could directly transduce the charge density changes based on the capture of target on the gate into the electrical signals using the OS-FET. The platform based on the FETs is suitable for a label-free, noncompetitive, and quantitative detection system for small antigen analysis in environmental, food, and clinical research.
Sakata
Toshiya
T
Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. sakata@biofet.t.u-tokyo.ac.jp
Ihara
Masaki
M
Makino
Izumi
I
Miyahara
Yuji
Y
Ueda
Hiroshi
H
D000941:Antigens / Q000032:analysis*; D001559:Benzhydryl Compounds; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D007147:Immunoglobulin Light Chains / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D017879:Isothiocyanates / Q000737:chemistry; D058619:Maltose-Binding Proteins; D010636:Phenols / Q000032:analysis; D014173:Transistors, Electronic; D000098826:Bisphenol A Compounds
D000941:Antigens; D001559:Benzhydryl Compounds; D002352:Carrier Proteins; D004492:Edetic Acid; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D017879:Isothiocyanates; D058619:Maltose-Binding Proteins; D010636:Phenols; C119668:isothiocyanobenzyl ethylenediamine tetracetic acid; C006780:bisphenol A; D000098826:Bisphenol A Compounds