An Impedimetric Nanosensor Based on Large-Scale Nanowell Array Electrode for Single Nucleotide Polymorphism of Leptin

Recently, we reported that the nanowell array (NWA) enhances electrochemical responses during the binding event of molecule to molecule through the binding site control of captured molecule. In this paper, we have demonstrated a method, with high sensitivity and selectivity for single nucleotide polymorphism detection of leptin, which is an established obesity biomarker. A 21-mer probe was immobilized on a nanowell array surface (500 nm diameter), which was coated with streptavidin and a self-assembled monolayer. The surface properties of probe oligomer hybridization with complementary target DNA were characterized using electro chemical impedance spectroscopy (EIS). Significant electric signal changes were observed at SNP oligomer compared with complementary target oligomer. We demonstrated that this SNP detection encompasses a range from 1 pM to 100 nM for quantitative analysis.