Mismatch detection in DNA monolayers by atomic force microscopy and electrochemical impedance spectroscopy

• DOI: 10.3762/bjnano.7.20
• Publication Date: 2016-02-09T09:34:13Z
• Authors: Maryse D Nkoua Ng...; Pietro Capaldo; Elena Ambrosetti; Giacinto Scoles; Loredana Casalis; Pietro Parisse
• Keywords: DNA–DNA hybridization

Background: DNA hybridization is at the basis of most current technologies for genotyping and sequencing, due to unique properties base-pairing that guarantee a high grade selectivity. Nonetheless presence single base mismatches or not perfectly matched sequences can affect response devices major challenge is, nowadays, distinguish mismatch and, same time, unequivocally differentiate read-out fully partially matching sequences. Results: We present here two platforms based on different sensing strategies, detect mismatched and/or complementary strands into ssDNA oligonucleotide monolayers. The first platform exploits atomic force microscopy-based nanolithography create nano-arrays gold surfaces. AFM topography measurements then monitor variation height nanostructures upon biorecognition follow annealing temperatures. This strategy allowed us clearly mismatches. second change in capacitance interface between an ssDNA-functionalized electrode solution process miniaturized electrochemical cell. Through impedance spectroscopy extended self-assembled monolayers we followed real-time capacitance, being able distinguish, through difference kinetics, only single, double triple sequence, but also position pair with respect surface. Conclusion: demonstrate strategies as sensitive selective tools discriminate Our assays are ready parallelization be used detection quantification nucleotide microRNAs genomic DNA.