Electrochemical DNA biosensor based on the proximity-dependent surface hybridization assay

作者：Zhang, Yanli; Wang, Ying; Wang, Haibo; Jiang, Jian-Hui^*; Shen, Guo-Li; Yu, Ru-Qin; Li, Jinghong

来源：Analytical Chemistry, 2009, 81(5): 1982-1987.

DOI：10.1021/ac802512d

• Complementary sequences
• DNA biosensors
• Dna detections
• Electrochemical dna biosensors
• Electrode surfaces
• Faradaic currents
• Ferrocene
• Gold electrodes
• High sensitivities
• Hybridization assays
• Low detection limits
• Redox currents
• Self
• assemblies
• Sensing systems
• Specific detections
• Wide dynamic ranges

This paper describes a novel electrochemical DNA (EDNA) biosensor for simple, rapid, and specific detection of nucleic acids based on the proximity-dependent surface hybridization assay. This E-DNA biosensor was constructed by self-assembly of a 3'short thiolated capture probe on the gold electrode. DNA detection was realized by outputting a remarkable redox current of the 5'ferrocene (Fc) tail labeled probe. When the target DNA was introduced into the system, it was complementary to the 5'Fc labeled probe at the one-half-segment and complementary to the 3'short thiolated capture probe at the other half-segment, resulting in forming a stable duplex complex. As a result, the Fc probe was proximate to the electrode surface, and the Faradaic current was observed. This E-DNA biosensor was proved to have a low detection limit (1 fM) and a wide dynamic range (from 1 fM to 1 nM) due to the stable hybridization mode. In addition, the sensing system could discriminate the complementary sequence from mismatch sequences, with high sensitivity, stability, and reusability.

• 单位
  清华大学