Nanoporous alumina membrane and nanoparticle based microfluidic sensing platform for direct DNA detection

Nucleic acids based detection has become increasingly important for biomedical diagnostics, environmental monitoring and food screening. In this paper, a nanoporous alumina membrane and nanoparticles based sensing platform has been developed for direct DNA detection. Single stranded DNA (ssDNA) was first covalently immobilized on the nanopore walls via (3-glycidoxypropyl) trimethoxysilane (GPMS). Double strand DNA (dsDNA) hybridization in the nanopores induced blockage in the nanopores, which could be detected by electrochemical impedance spectroscopy (EIS). The blockage signal was then amplified by DNA with gold nanoparticles (AuNPs) and silver catalytic deposition method. This platform is promising for simple, rapid and sensitive DNA detection.