Sequence-specific detection of trace DNA via a junction-probe electrochemical sensor employed template-enhanced hybridization strategy.
A novel junction-probe electrochemical biosensor for the sequence-specific detection of DNA with higher sensitivity and higher discrimination ability was described in here. This DNA biosensor is based on "junction-probe" detection strategy, which operates via a concept called template-enhanced hybridization processes (TeHyP). TeHyP encompasses a design strategy whereby two probes that do not hybridize to each other at a specific temperature can be made to anneal to each other in the presence of a template (target) via the formation of a ternary complex ("Y" junction structure). The resulting structure that forms after the template-enhanced hybridization then was detected by electrochemical method with [Ru(NH(3))(6)](3+) as signal molecule. We demonstrated that the formation of "Y" junction structure brings more [Ru(NH(3))(6)](3+) to the electrode surface via electrostatic interaction and results in an increasing electrochemical signal. The increasing electrochemical signal sensitively reflects the concentration of target DNA and shows a good linear relationship with the concentration of target DNA. By employing above strategy, this DNA biosensor could detect as low as 7.6 x10(-13)M target DNA and exhibited high discrimination ability even against single-base mismatch. In addition, this novel DNA biosensor is easy to fabricate and convenient to operate, and shows good stability, reproducibility and reusability.
Zhang
Jing
J
Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China.
Chen
Jing Hua
JH
Chen
Rong Chun
RC
Chen
Guo Nan
GN
Fu
Feng Fu
FF
D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation; D004247:DNA / Q000737:chemistry* / Q000235:genetics*; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017403:In Situ Hybridization / Q000295:instrumentation*; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D012666:Semiconductors; D017422:Sequence Analysis, DNA / Q000295:instrumentation*
D004247:DNA