Label-free, Fluorescence Detection of DNA on Nanoparticle Scaffolds

摘要

We have developed a nanoparticle-based DNA biosensor that can detect unlabelled ssDNA with good selectivity and decent sensitivity. The biosensor makes use of the optical changes of a cationic polymer interacting with ssDNA versus that of hybridized DNA to provide a fluorescence signal only when a specific hybridization event occurs (i.e. only when perfectly complementary DNA is present). Through monitoring this change in fluorescence intensity this nanoparticle-based biosensor can detect of fewer than 5 pmol of ss-DNA in a 1 mL sample (i.e. has a limit of detection of 5 nM ssDNA).