Desenvolvimento de Imunossensor EletroquÃmico para detecÃÃo do AntÃgeno ProstÃtico EspecÃfico (PSA) empregando eletrodo de ouro

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Prostatic Specific Antigen (PSA) is a valuable biomarker for prostate cancer screening. For PSA determination, the immunosensors emerge as a very attractive technique due to its simplicity, specificity and less time for analysis when compared to conventional techniques of immunoassays. An immunosensor based on a gold electrode was used in an electrochemical system for the determination of PSA. The monoclonal antibody against PSA (Anti-PSA) was oriented on the gold electrode surface via protein A, used for a better orientation of the antibodies in the SAM (Self-Assembled Monolayers), that were formed incubating the electrode in a solution of 2-aminoethanethiol (25mM) followed by glutaraldehyde 2.5% (v/v) for 45min. The amount of anti-PSA immobilized on the gold electrode, modified by SAM of thiol, using protein A was 27% higher than control (without protein A). Optimal parameters were established to a good performance of immunosensors: incubation time (20min) and pH (7.0 â 7.5). The calibration curve achieved linearity (r=0.997, p<0,0001) and good reproducibility with relative error less than 5% when the PSA antigen was incubated at concentrations varying from 1.0 to 15 ng/mL at 25oC. The results obtained were satisfactory proving the viability on the immunosensors development to determination of PSA

ASSUNTO(S)

protein a psa imunossensor psa monocamadas auto-organizadas bioquimica immunosensor proteÃna a sam

ACESSO AO ARTIGO

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