A novel electrochemical DNA biosensor construction based on layered CuS–graphene composite and Au nanoparticles
| Autor: | Lu Lu, Qiu-Ge Zhai, Ke-Jing Huang, Ke-Xin Li, Yu-Jie Liu, Chun-Xuan Xu |
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| Rok vydání: | 2014 |
| Předmět: |
Detection limit
Materials science Base Sequence Graphene Metal Nanoparticles Nanoparticle Nanotechnology Biosensing Techniques DNA Biochemistry Analytical Chemistry law.invention Dielectric spectroscopy Chemical engineering law Colloidal gold Microscopy Electron Scanning Gold Differential pulse voltammetry Cyclic voltammetry DNA Probes Biosensor Copper |
| Zdroj: | Analytical and Bioanalytical Chemistry. 406:6943-6951 |
| ISSN: | 1618-2650 1618-2642 |
| DOI: | 10.1007/s00216-014-7904-7 |
| Popis: | A novel CuS-graphene (CuS-Gr) composite was synthesized to achieve excellent electrochemical properties for application as a DNA electrochemical biosensor. CuS-Gr composite was prepared by a hydrothermal method, in which two-dimensional graphene served as a two-dimensional conductive skeleton to support CuS nanoparticles. A sensitive electrochemical DNA biosensor was fabricated by immobilizing single-stranded DNA (ss-DNA) labeled at the 5' end using 6-mercapto-1-hexane (HS-ssDNA) on the surface of Au nanoparticles (AuNPs) to form ssDNA-S-AuNPs/CuS-Gr, and hybridization sensing was done in phosphate buffer. Cyclic voltammetry and electrochemical impedance spectroscopy were performed for the characterization of the modified electrodes. Differential pulse voltammetry was applied to monitor the DNA hybridization using an [Fe(CN)6](3-/4-) solution as a probe. Under optimum conditions, the biosensor developed exhibited a good linear relationship between the current and the logarithm of the target DNA concentration ranging from 0.001 to 1 nM, with a low detection limit of 0.1 pM (3σ/S). The biosensor exhibited high selectivity to differentiate one-base-mismatched DNA and three-base-mismatched DNA. The results indicated that the sensing platform based on CuS-Gr provides a stable and conductive interface for electrochemical detection of DNA hybridization, and could easily be extended to the detection of other nucleic acids. |
| Databáze: | OpenAIRE |
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