An Electrochemical DNA Sensing System Using Modified Nanoparticle Probes for Detecting Methicillin-Resistant Staphylococcus aureus
We have developed a novel, highly sensitive, biosensing system for detecting methicillin-resistant Staphylococcus aureus (MRSA). The system employs gold nanoparticles (AuNPs), magnetic nanoparticles (mNPs), and an electrochemical detection method. We have designed and synthesized ferrocene- and single-stranded DNA-conjugated nanoparticles that hybridize to MRSA DNA. Hybridized complexes are easily separated by taking advantage of mNPs. A current response could be obtained through the oxidation of ferrocene on the AuNP surface when a constant potential of +250 mV vs. Ag/AgCl is applied. The enzymatic reaction of l-proline dehydrogenase provides high signal amplification. This sensing system, using a nanoparticle-modified probe, has the ability to detect 10 pM of genomic DNA from MRSA without amplification by the polymerase chain reaction. Current responses are linearly related to the amount of genomic DNA in the range of 10–166 pM. Selectivity is confirmed by demonstrating that this sensing system could distinguish MRSA from Staphylococcus aureus (SA) DNA.
Key wordsDNA biosensor Nanoparticle Electrochemical detection Magnetic separation Chronoamperometry
This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting, and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. The definitive version has been published in Biosensor and Bioelectronics, VOLUME 67, SPECIAL ISSUE BIOSENSORS 2014, May 15, DOI: 10.1016/j.bios.2014.08.075
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