1.Department of Medical Physics and Biomedical Engineering, School of Medicine,Shahid Beheshti University of Medical Sciences,Tehran,Iran;2.Department of Physics,Sharif University of Technology,Tehran,Iran;3.Department of Microbiology, School of Medicine,Shahid Beheshti University of Medical Sciences,Tehran,Iran;4.Institute for Nanoscience and Nanotechnology (INST),Sharif University of Technology,Tehran,Iran
Abstract:
The authors describe an impedimetric method for the quantitation of the DNA of the human papilloma virus (HPV) type 16. A glassy carbon electrode (GCE) was modified with gold nanosheets and is shown to be superior to a common gold disk electrode. A single-stranded 25mer oligonucleotide (ssDNA) acting as the probe DNA was immobilized via its thiolated 5′ end on both electrodes. After hybridization with target (analyte) DNA, electrochemical impedance spectra were acquired in the presence of hexacyanoferrate as a redox marker. The sensor can distinguish between complementary, non-complementary and single base pair mismatches of HPV ssDNA. At a 1 mM hexacyanoferrate concentration, the biosensors respond to target DNA in the 1 μM to 1 pM concentration range, and the detection limit is 0.15 pM. The results illustrate that the use of gold nanosheets on a GCE distinctly improves the detection and differentiation of HPV compared to using bare gold.
Graphical abstract Schematic of exploiting gold nanosheets as a platform for HPV detection. The method works in the 1 μM to 1 pM HPV concentration range and has a 0.15 pM detection limit..
