Reduced graphene-oxide transducers for biosensing applications beyond the Debye-screening limit.
Biosens Bioelectron
; 130: 352-359, 2019 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-30269960
ABSTRACT
In the field of label-free biosensing, various transducer materials and strategies are under investigation to overcome the Debye-screening limitation of charged biomolecules. We demonstrate an in-line, impedimetric aptasensor with reduced graphene-oxide (rGO) thin films as transducers to detect prostate specific antigens (PSA) in a physiological buffer solution. Unlike classical electrochemical impedance spectroscopy (EIS), this direct, label-free and fully-electronic biosensor approach does not need any redox markers. As specific capture molecules, short anti-PSA aptamers ensured a close binding of the target molecules to the transducer surfaces. Results showed a limit of detection smaller than 33â¯pM of PSA and a wide detection range from 0.033 to 330â¯nM fully covering the clinically relevant range of PSA (0.115-0.290â¯nM). This promising performance can be attributed to the bipolar electronic transport characteristics of the ultra-thin rGO layers similar to pristine graphene. The attachment of target biomolecules to the films changes the resistance of the rGO thin films. Such an in-line EIS configuration with rGO thin films opens promising prospects for biosensing beyond the Debye-screening limitation, which is a major challenge for conventional semiconductor field-effect devices towards clinical applications.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
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Antígeno Prostático Específico
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Técnicas Eletroquímicas
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Grafite
Tipo de estudo:
Diagnostic_studies
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Screening_studies
Limite:
Humans
Idioma:
En
Revista:
Biosens Bioelectron
Assunto da revista:
BIOTECNOLOGIA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Alemanha