A simple and sensitive resonance light scattering method based on aggregation of gold nanoparticles for selective detection of microRNA-21

Abstract

We describe a simple, sensitive and selective resonance light scattering (RLS) method based on analyte-induced aggregation of gold nanoparticles (GNs) for the determination of microRNAs (miRNAs). The RLS sensor is fabricated by modifying GNs with two strands of cDNA sequence, which can averagely complement the target miRNA. When the target miRNA is introduced, the cDNAs can complement the target miRNAs, thereby forming a cDNA\RNA heteroduplex. The formation of cDNA\RNA heteroduplex led to the aggregation of GNs, which promotes RLS enhancement. A limit of detection of 2.21 pM and a liner range from 10 to 200 nM (R² = 0.9981) are achieved using this assay. Moreover, this strategy was further used for the determination of miRNAs in a human serum sample with satisfying results, offering a significant potential for clinical application.