University of Nebraska-Lincoln
Chemical & Biomolecular Engineering
215 OTHMER HALL
Lincoln NE 68588-0643 USA
• Measurement of ionic concentration fluctuations due to 'live' process in a micro-organism. The in-situ measurement of the change in the local extra-cellular ionic content of the cells, as result of the biochemical activities initiated, due to oxidative stress will lead to new insights towards cellular oxidative damage coping mechanisms. For example, yeast cells, used as a model living organism, can be immobilized on a gold electrode and ion dynamics in the EDL formed at the metal-electrolyte interface can be probed by applying a small alternating potential to the electrode.
• "Nano-sieves" based on polyelectrolyte motion through tortuous path. Separation of biological moieties is usually carried out on the basis of the size and/or charge of the molecules e.g., column separations and gel electrophoresis. However, separation techniques at single molecule level are still not fully developed. Exploiting the sensitive measurement of the polyelectrolyte accumulation at the metal electrode, after passing through a multi-layer film, we can fabricate "nano-sieves" to detect analyte of interest based on the charge and the chain conformation. The "sieve size" of the multi-layer film formed by self- assembly of insulation nanoparticles can be tuned by varying the size and shape of the nanoparticles.
• Single electron effects on Nano-Electrodes. The quantized double layer charging of gold nanoparticles immobilized on electrodes has been demonstrated in literature. The optical signature of this phenomenon can be observed by our differential interferometer provided the gold nanoparticles are sufficiently mono-dispersed in size. On immobilization of electro-active proteins to these nanoparticles, the effect of single electron transfer to and from the protein can be monitored by observing the ion charging at the electrodes.
Optical Properties of an Immobilized DNA Monolayer from 255 to 700 nm, Dr.Ravi F. Saraf, Gaurav Singh, and Selim Elhadj
Solid-like dynamics in ultrathin films of polymeric liquids, Gaurav Singh and Ravi F. Saraf
Solid-like dynamics in ultrathin films of polymeric liquids, Gaurav Singh, Ravi Saraf, and Yves Martin