Ultrasensitive Label-Free DNA Detection Based on Solution-Gated Graphene Transistors Functionalized with Carbon Quantum Dots
Authors
Affiliations
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.
Savas S, Saricam M Micromachines (Basel). 2024; 15(11).
PMID: 39597120 PMC: 11596170. DOI: 10.3390/mi15111308.
Shao W, Zeng Z, Star A ACS Appl Mater Interfaces. 2023; 15(31):37784-37793.
PMID: 37523478 PMC: 10416144. DOI: 10.1021/acsami.3c05958.
Chen S, Sun Y, Fan X, Xu Y, Chen S, Zhang X J Nanobiotechnology. 2023; 21(1):144.
PMID: 37122015 PMC: 10148958. DOI: 10.1186/s12951-023-01898-z.
Krishnan S, Nataraj N, Meyyappan M, Pal U Anal Chem. 2023; 95(5):2590-2622.
PMID: 36693046 PMC: 11386440. DOI: 10.1021/acs.analchem.2c03399.
Deng M, Ren Z, Zhang H, Li Z, Xue C, Wang J Adv Sci (Weinh). 2022; 10(4):e2205886.
PMID: 36480308 PMC: 9896035. DOI: 10.1002/advs.202205886.