A Versatile Dynamic Light Scattering Strategy for the Sensitive Detection of Plant MicroRNAs Based on Click-Chemistry-Amplified Aggregation of Gold Nanoparticles

Plant microRNAs (miRNAs) are naturally 2'-O-methylated at the 3'-terminal; as a consequence, they cannot be efficiently detected by traditional target-triggered polymerization reactions. Here, a simple but robust enzyme-free sensing strategy was developed for plant miRNA analysis by using dynamic light scattering (DLS) to monitor the crosslinking of gold nanoparticles (AuNPs) amplified by click chemical ligation. Combining the enzyme-free cycling chemical-ligation-mediated signal amplification, and the intrinsic outstanding ability of DLS for discriminating the extremely low level of particle aggregation in a large pool of monodisperse AuNPs, high sensitivity was achieved and as low as 78.6 fM plant miRNA could be easily detected.