Ultrasensitive Label-Free DNA Detection Based on Solution-Gated Graphene Transistors Functionalized with Carbon Quantum Dots.
Anal Chem
; 94(7): 3320-3327, 2022 02 22.
Article
em En
| MEDLINE
| ID: mdl-35147418
ABSTRACT
Developing highly sensitive, reliable, cost-effective label-free DNA biosensors is challenging with traditional fluorescence, electrochemical, and other techniques. Most conventional methods require labeling fluorescence, enzymes, or other complex modification. Herein, we fabricate carbon quantum dot (CQD)-functionalized solution-gated graphene transistors for highly sensitive label-free DNA detection. The CQDs are immobilized on the surface of the gate electrode through mercaptoacetic acid with the thiol group. A single-stranded DNA (ssDNA) probe is immobilized on CQDs by strong π-π interactions. The ssDNA probe can hybridize with the ssDNA target and form double-stranded DNA, which led to a shift of Dirac voltage and the channel current response. The limit of detection can reach 1 aM which is 2-5 orders of magnitude lower than those of other methods reported previously. The sensor also exhibits a good linear range from 1 aM to 0.1 nM and has good specificity. It can effectively distinguish one-base mismatched target DNA. The response time is about 326 s for the 1 aM target DNA molecules. This work provides good perspectives on the applications in biosensors.
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Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
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Pontos Quânticos
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Grafite
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article