DNA impedance biosensor for detection of cancer, TP53 gene mutation, based on gold nanoparticles/aligned carbon nanotubes modified electrode

Carbon nanotube biosensors

“…Fayazfar et al reported on a new platform based on electrochemical growth of gold nanoparticles on aligned MWNTs for sensitive label-free DNA detection of the TP53 gene mutation (Figure 7B ; Fayazfar et al, 2014 ). The electrode modified with vertically aligned MWNTs and gold nanoparticles improved the density of the DNA probe as well as the sensor sensitivity, displayed reproducibility and stability for 2 weeks, and could be conveniently regenerated via dehybridization in hot water.…”

Electrochemical Immunosensor Based on Antibody-Nanoparticle Hybrid for Specific Detection of the Dengue Virus NS1 Biomarker

“…However, when AuNPs were attached, there was a significant decrease in the R ct (Figure 1aIII and Table I), and this observation is consistent with other studies showing that AuNPs can decrease the resistance of charge transfer when they are attached to blocking layers. 32,33 The deposition of 1,4-phenylenediamine caused an increase in the R ct (Figure 1aIV and Table I), and further increases in the R ct were detected when monoclonal anti-NS1 IgG antibodies were covalently bound to 1,4-phenylenediamine by using EDC/NHS (Figure 1aV and Table I). Moreover, an increase in the R ct was observed when the NS1 antigen bound specifically to the monoclonal anti-NS1 IgG antibody layer.…”

Highly sensitive electrochemical detection of genomic DNA based on stem loop probes structured for magnetic collection and measurement via metalised hollow polyelectrolyte shells

“…50 aM using Au nanoparticles (Rasheed and Sandhyarani, 2015), 0.2 fM using exonuclease III assisted target recycling with methylene blue as redox indicator (Ren et al, 2015), 1 fM using rolling circle amplification with detection via alkaline phosphatase catalysis (Cheng et al, 2014), 13 aM using horseradish peroxidase labels to generate benzoquinone (Sun et al, 2015), 42 fM using target-catalysed displacement of ferrocene-tagged sequences from stem loop probes (Qian et al, 2014), 4 fM using ferrocene-tagged Au nanoparticles with PCR amplicons (Qiu et al, 2014), 20 fM using exonuclease III assisted target recycling with methylene blue, 10 aM using the change in impedance spectroscopy of Fe(CN) 6 3-/4-at an electrode modified by aligned carbon nanotubes modified by Au nanoparticles (Fayazfar et al, 2014), 0.25 fM using exonuclease assisted target recycling with hemin as redox indicator , with the exception of the report by Benvidi et al (2014) (3.2 zM using the change in impedance spectroscopy of Fe(CN) 6 3-/4-at a reduced graphene-coated electrode). However, this report required 35 PCR cycles to amplify the quantity of genomic DNA being detected.…”