Label-free electrochemical detection of DNA using ferrocene-containing cationic polythiophene and PNA probes on nanogold modified electrodes.
A label-free electrochemical method for the detection of DNA-PNA hybridization using a water-soluble, ferrocene-functionalized polythiophene transducer and single-stranded PNA probes on the nanogold modified electrode is investigated. Nanogold modified electrodes can largely increase the immobilization amount of ss-PNA capture probe and lead to an increase of the electrical signal. The ferrocene-containing cationic polythiophene do not interact electrostatically with the PNA probes due to the absence of the anionic phosphate groups on the PNA probes. But after DNA-PNA hybridization, cationic polythiophene is adsorbed on the DNA backbone, giving a clear hybridization detection signal in differential pulse voltammetry (DPV). Very good discrimination against non-complementary DNA and four-base mismatch DNA is observed. These studies show that the proposed method can provide an alternative for expanding the range of detection methods available for DNA hybridization.
Fang
Bin
B
College of Chemistry and Materials Science, Anhui Normal University, Wuhu, China. binfang_47@yahoo.com.cn
Jiao
Shoufeng
S
Li
Maoguo
M
Qu
Yuan
Y
Jiang
Ximing
X
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002412:Cations; D004247:DNA / Q000737:chemistry / Q000235:genetics*; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D008839:Microelectrodes; D049329:Nanostructures / Q000737:chemistry*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000295:instrumentation / Q000379:methods; D013194:Staining and Labeling; D013876:Thiophenes / Q000737:chemistry*
D002412:Cations; D015342:DNA Probes; D020135:Peptide Nucleic Acids; D011108:Polymers; D013876:Thiophenes; C066730:polythiophene; D006046:Gold; D004247:DNA