Impedimetric evaluation for diagnosis of Chagas' disease: antigen-antibody interactions on metallic electrodes.
A polypeptide chain formed by recombinant antigens, cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) (CF-Chimera) of Trypanosoma cruzi, was adsorbed on gold and platinum electrodes and investigated by electrochemical impedance spectroscopy on phosphate buffer saline solutions (PBS) containing a redox couple. It was found that the adsorption is strongly sensitive to the oxide layer on the electrode surface. In the majority of the experiments the antigens retained their activity as observed through their interaction with sera from chronic chagasic patients. The results expressed in terms of the charge transfer resistance across the interface, indicate the viability of using the impedance methodology for the development of a biosensor for serological diagnosis of Chagas' disease.
Diniz
Flamarion B
FB
Laboratório de Eletroquímica, Departamento de Química Fundamental, Universidade Federal de Pernambuco, Cidade Universitária, 50670-901 Recife, PE, Brazil. fbd@ufpe.br
Ueta
Roseli R
RR
Pedrosa
Alziana M da C
AM
Areias
Madalena da C
Mda C
Pereira
Valéria R A
VR
Silva
Edimilson D
ED
da Silva
José Godinho
JG
Ferreira
Antônio G P
AG
Gomes
Yara M
YM
D000906:Antibodies / Q000097:blood* / Q000276:immunology; D000936:Antigen-Antibody Complex / Q000097:blood* / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D014355:Chagas Disease / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D008670:Metals; D010984:Platinum; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000295:instrumentation / Q000379:methods
D000906:Antibodies; D000936:Antigen-Antibody Complex; D020099:Coated Materials, Biocompatible; D008670:Metals; D010984:Platinum; D006046:Gold