Single Molecule Trapping and Sensing Using Dual Nanopores Separated by a Zeptoliter Nanobridge

There is a growing realization, especially within the diagnostic and therapeutic community, that the amount of information enclosed in a single molecule can not only enable a better understanding of biophysical pathways, but also offer exceptional value for early stage biomarker detection of disease onset. To this end, numerous single molecule strategies have been proposed, and in terms of label-free routes, nanopore sensing has emerged as one of the most promising methods. However, being able to finely control molecular transport in terms of transport rate, resolution, and signal-to-noise ratio (SNR) is essential to take full advantage of the technology benefits. Here we propose a novel solution to these challenges based on a method that allows biomolecules to be individually confined into a zeptoliter nanoscale droplet bridging two adjacent nanopores (nanobridge) with a 20 nm separation. Molecules that undergo confinement in the nanobridge are slowed down by up to 3 orders of magnitude compared to conventional nanopores. This leads to a dramatic improvement in the SNR, resolution, sensitivity, and limit of detection. The strategy implemented is universal and as highlighted in this manuscript can be used for the detection of dsDNA, RNA, ssDNA, and proteins

Self-Assembled Spherical Supercluster Metamaterials from Nanoscale Building Blocks

We report on a simple, universal, and large-scale self-assembly method for generation of spherical superclusters from nanoscopic building blocks. The fundamentals of this approach rely on the ultrahigh preconcentration of nanoparticles (NP) followed by using either emulsification strategies or alternatively multiphase microfluidic microdroplets. In both cases drying of the NP droplets yields highly spherical self-assembled superclusters with unique optical properties. We demonstrate that the behavior of these spheres can be controlled by surface functionalization before and after the self-assembly process. These structures show unique plasmonic collective response both on the surface and within the supercluster in the visible and infrared regions. Furthermore, we demonstrate that these strong, tunable optical modes can be used toward ultrasensitive, reproducible, surface-enhanced spectroscopies