Abstract

In this talk I will present two areas of research in my group. Firstly, our work on electrochemical, label-free gene sensors based on conjugated polymers, and secondly on our conductive polymer systems grafted with stimuli responsive polymer brushes. Poor specificity, low sensitivity, high labour cost and false positive/negative signals are outstanding issues in gene sensing and have propelled the development of new sensing methodologies and devices. To address some of these issues, we are developing a range of gene sensors based on derivatives of conjugated polymers (CPs). These sensors are based on (i) the electrochemical transduction of the hybridization event by the CP thin films measured by electrochemical impedance spectroscopy; (ii) optical readouts based on either FRET (fluorescence resonance energy transfer) or quenching of photoluminescence of conjugated polymers. Electrochemical detection methodologies in particular provide a simple, direct electrical and label-free gene sensing. Devices constructed with single conducting copolymer nanowires, as a label-free oligonucleotide sensors with sensitivities in fM range, will be outlined, as well as our recent work on development of a label free, electrochemical, real time detection of the polymerize chain reaction (PCR). Grafting polymeric side chains onto conjugated polymers provide a versatile route towards designer conjugated polymers with added functionality, tunability in their opto-electronic properties, processability and responsiveness to stimuli. Our approaches to such materials will be outlined and possible applications in biomedical and bioengineering fields discussed.