A gold nanoparticle-based chronocoulometric DNA sensor for amplified detection of DNA.
We report a protocol for the amplified detection of target DNA by using a chronocoulometric DNA sensor (CDS). Electrochemistry is known to be rapid, sensitive and cost-effective; it thus offers a promising approach for DNA detection. Our CDS protocol is based on a 'sandwich' detection strategy, involving a capture probe DNA immobilized on a gold electrode and a reporter probe DNA loaded on gold nanoparticles (AuNPs). Each probe flanks one of two fragments of the target sequence. A single DNA hybridization event brings AuNPs, along with hundreds of reporter probes, in the proximity of the electrode. We then employ chronocoulometry to interrogate [Ru(NH3)6]3+ electrostatically bound to the captured DNA strands. This AuNP-amplified DNA sensor can selectively detect as low as femtomolar (zeptomoles) concentrations of DNA targets and conveniently analyze a breast cancer-associated BRCA-1 mutant DNA. The time range for the entire protocol is approximately 3 d, whereas the DNA sensing takes less than 2 h to complete.
Zhang
Jiong
J
Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
Song
Shiping
S
Wang
Lihua
L
Pan
Dun
D
Fan
Chunhai
C
D015374:Biosensing Techniques; D002623:Chemistry Techniques, Analytical; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D004252:DNA Mutational Analysis; D004566:Electrodes; D019398:Genes, BRCA1; D006046:Gold; D006801:Humans; D006824:Hybridization, Genetic; D053768:Metal Nanoparticles
D006046:Gold; D004247:DNA