Preparation and application of AgNPs/SWCNTs nanohybrid as an electroactive label for sensitive detection of miRNA related to lung cancer

摘要

An electrochemical nanogenosensor based on silver nanoparticles/single-walled carbon nanotubes nanohybrid (AgNPs/SWCNTs nanohybrid), as a label, was developed for the analysis of miRNA (miR-25) related to lung cancer. The preparation steps of the proposed nanogenosensor were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The two components of the AgNPs/SWCNTs nanohybrid have different roles in the nanogenosensor performance. SWCNTs are responsible for interaction with the probe, while AgNPs produce electroanalytical signals. It was shown that the π-π interaction between the AgNPs/SWCNTs nanohybrid and the nitrogenous bases related to double-stranded nucleic acid is weaker than that for single-stranded nucleic acid. The different abilities of AgNPs/SWCNTs nanohybrid to bind with the probe hybridized with complementary (miRNA related to lung cancer), non-complementary and one-base mismatch targets led to identification of the nature and the concentration of miRNA through a simple and fast approach. The developed nanogenosensor was used to determine miR-25 in two concentration ranges of 1.0 × 10−12to 1.0 × 10−10 M and 1.0 × 10−10to 1.0 × 10−8 M with a limit of detection (LOD) of 3.13 × 10−13 M without PCR amplification. Furthermore, the nanogenosensor was employed to detect miR-25 in human plasma. This electrochemical procedure can be valuable in genetic analysis and early clinical diagnosis.