Electrochemical immunosensing using micro and nanoparticles.
A model immunosensor based on a labeling method using gold nanoparticles (AuNPs) and electrochemical detection is developed. Microparamagnetic beads (MB) as primary antibody immobilization platforms and AuNPs modified with a secondary antibody as high sensible electrochemical labels have been used. The carbon electrode used as transducer incorporates a magnet that allows the collection/ immobilization on its surface of the immunological sandwich attached to the MB. Briefly, the sandwich type assay consists in the incubation of streptavidin-coupled-MB with an antihuman IgG biotin conjugate, and then, the immunological reaction with the human IgG antigen takes place. After that, a gold labeled anti-human IgG reacts with the antigen, and finally the AuNPs are electrochemically detected. This approach allows the obtaining of an immunosensor with a low antigen detection limit with special interest for several applications in protein analysis.
de la Escosura-Muñiz
Alfredo
A
Nanobioelectronics & Biosensors Group, Institut Català de Nanotecnologia, Barcelona, Catalonia, Spain.
Ambrosi
Adriano
A
Alegret
Salvador
S
Merkoçi
Arben
A
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D007074:Immunoglobulin G / Q000032:analysis*; D008839:Microelectrodes; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007074:Immunoglobulin G