Design of molecularly imprinted conducting polymer protein-sensing films via substrate-dopant binding.

Addressing the challenge of protein biosensing using molecularly imprinted polymers (MIP), we have developed and tested a novel approach to creating sensing conducive polymer films imprinted with a protein substrate, ricin toxin chain A (RTA). Our approach for creating MIP protein sensing films is based on a concept of substrate-guided dopant immobilization with subsequent conducting polymer film formation. In this proof-of-concept work we have tested three macromolecular dopants with strong protein affinity, Ponceau S, Coomassie BB R250 and ι-Carrageenan.

Real-time and label-free analyte detection in a flow-through mode using immobilized fluorescent aptamer/quantum dots molecular switches.

Inspired by the goal to create a biosensor with designer specificity for real-time detection of unlabeled analytes in a flow-through mode, we designed a miniature flow cell with interchangeable quartz window carrying immobilized aptamer/quantum dot molecular switches as a part of a portable fluorescent setup. The inner surface of the 1.5mm ID, 12µl flow cell quartz window has been modified with the aptamer sensing complexes containing highly-fluorescent quantum dots.

Real-time aptamer quantum dot fluorescent flow sensor.

The goal of this work was to develop and test a novel real-time biosensing approach which can be adapted to either environmental or clinical monitoring of biological pathogens. We have developed a working prototype of a real-time aptamer-based fluorescent flow sensor. The sensor utilizes a competitive displacement approach to measure the binding of the analyte, which keeps the nonspecific binding below detectable levels.

Direct electrochemical sensor for fast reagent-free DNA detection.

A novel reagentless direct electrochemical DNA sensor has been developed using ultrathin films of the conducting polymer polypyrrole doped with an oligonucleotide probe. Our goal was to develop a prototype electrochemical DNA sensor for detection of a biowarfare pathogen, variola major virus. The sensor has been optimized for higher specificity and sensitivity.