Massively Parallel and Highly Quantitative Single-Particle Analysis on Interactions between Nanoparticles on Supported Lipid Bilayer

Observation of individual single-nanoparticle
reactions provides
direct information and insight for many complex chemical, physical,
and biological processes, but this is utterly challenging with conventional
high-resolution imaging techniques on conventional platforms. Here,
we developed a photostable plasmonic nanoparticle-modified supported
lipid bilayer (PNP-SLB) platform that allows for massively parallel
in situ analysis of the interactions between nanoparticles with single-particle
resolution on a two-dimensional (2D) fluidic surface. Each particle-by-particle
PNP clustering process was monitored in real time and quantified via
analysis of individual particle diffusion trajectories and single-particle-level
plasmonic coupling. Importantly, the PNP-SLB-based nanoparticle cluster
growth kinetics result was fitted well. As an application example,
we performed a DNA detection assay, and the result suggests that our
approach has very promising sensitivity and dynamic range (high attomolar
to high femtomolar) without optimization, as well as remarkable single-base
mismatch discrimination capability. The method shown herein can be
readily applied for many different types of intermolecular and interparticle
interactions and provide convenient tools and new insights for studying
dynamic interactions on a highly controllable and analytical platform.