The exploration of individual and freely suspended small particles in liquids is presently impaired by Brownian motion which makes a prolonged spectroscopic investigation difficult and for sub 100 nm scaled particles impossible. The proposed instrument will address this challenge through the development of a nanoparticle trap that is expected to allow the positioning, alignment and tracking of individual particles with diameters down to 10 nm. The instrument utilizes novel techniques for interferometric confocal particle detection with high sensitivity and bandwidth, and combines this with feedback controlled electrokinetic or mechanical manipulation of liquid flow in a microfluidic device. Spectroscopic characterization of trapped objects will initially be done using CW and time-resolved fluorescence measurements. The proposed instrument development will thereby provide an interdisciplinary team of researchers from Chemistry-, Pharmacology- and Physics Departments with a unique tool for spectroscopic exploration of individual micron or nano-scale objects in liquid environment. It is envisioned that this instrument may also be used as versatile tool for life sciences allowing prolonged investigation and tracking of viruses, bacteria or self-propelled organisms. The project is coupled to an educational component that consists of training of undergraduate and graduate students with the use of basic as well as advanced optical technologies.
As the exploration of the nano and micro-cosmos pushes towards new frontiers, challenges emerge that can prevent scientific progress in certain areas. One such challenge are the difficulties encountered with the investigation of individual sub-micron sized objects in liquids. This is due to Brownian motion which sends particles on a random path and makes prolonged investigation by spectroscopic or other means difficult if not impossible. The proposed instrument will help overcome such limitations through the development of a particle trap which will allow positioning, alignment and tracking of objects with diameters down to a few nanometers. This instrument is thereby expected to furnish an interdisciplinary team of researchers from Chemistry, Pharmacology and Physics Departments with a unique and versatile tool for spectroscopic investigations under previously inaccessible conditions. Moreover, it is envisioned that such an instrument may be used as a tool for life sciences, opening new horizons by allowing prolonged investigation and tracking of viruses, bacteria or self-propelled organisms. Research programs drawing on the use of this instrument are expected to benefit the discovery and development of more efficient materials for solid state light sources and better opto- or nanoelectronic devices for future electronic applications.