A ternary CdS@Au-g-C3N4 heterojunction-based photoelectrochemical immunosensor for prostate specific antigen detection using graphene oxide-CuS as tags for signal amplification.
Anal Chim Acta
; 1106: 183-190, 2020 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-32145847
ABSTRACT
Photoactive materials with high photo-electron transfer efficiency and stable signal output hold a key role in constructing the photoelectrochemical (PEC) biosensing systems. In this study, the ternary CdS@Au-g-C3N4 heterojunction was first prepared and characterized, and its application in PEC bioanalysis was explored. The gold nanoparticles sandwiched between CdS and g-C3N4, acting as both plasmonic photosensitizer and electron relay, significantly boosted the light absorption and accelerated the charge transfer from g-C3N4 to CdS, both of which contributed to the enhancement of photoelectric conversion efficiency. Signal quenching with graphene oxide-CuS efficiently weakened the photocurrent from CdS@Au-g-C3N4. The combination of the excellent PEC properties of CdS@Au-g-C3N4 and the remarkable quenching effects of graphene oxide-CuS enabled construction of a sandwich-type PEC immunosensor for prostate specific antigen (PSA) detection. This immunosensor achieved sensitive PSA analysis by multiple signal amplification mechanisms, with a detection limit of 0.6 pg mL-1 and a wide linear range from 1.0 pg mL-1 to 10 ng mL-1. This work not only demonstrates the great potential of noble metal sandwiched ternary heterojunctions in the PEC field, but also lays a foundation for developing the general PEC immunoassays.
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MEDLINE
Assunto principal:
Imunoensaio
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Técnicas Biossensoriais
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Antígeno Prostático Específico
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Técnicas Eletroquímicas
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article