CEE Seminar Speaker Dr. Tonya Kuhl

Title: Tuning Polydiacetylene Surfactants and Their Assemblies for Biosensing Applications

Abstract: Surfactant diacetylene molecules can be polymerized to make inexpensive polydiacetylene (PDA) sensors that transform from visibly blue to red and from non-fluorescent to highly fluorescent upon exposure to sufficient thermal, mechanical, or radiative stimuli. Tuning the threshold and range of this response is essential for detecting weak biological signals. The talk will describe high-quality PDA Langmuir films and vesicles and show how tail length, headgroup chemistry, ions and lipid dopants tune vesicle assembly, polymerization, and stimulus sensitivity. Shorter tail-length and ethanolamine headgroup functionalization lower thermal switching thresholds, while boronic acid functionalization increases the threshold. Notably, selected saturated lipid dopants accelerate polymerization and produce a graded response to temperature. The broadened chromatic transition converts the sensor's behavior from a thresholdbased (binary) response into a proportional (analog) response - a dramatic capability enhancement that significantly expands the utility of PDA-based sensors. These effects can be understood in terms of stress placed on the polydiacetylene backbone that promote or inhibit the transition from the blue to red phase. Example applications will include two-dimensional films that report cell-generated shear stresses and three-dimensional vesicle sensors embedded in hydrogels for sensing contractions of single cardiomyocytes (heart cells).
https://drive.google.com/drive/u/0/folders/15UgQuafQG1-XOKIKufX0saDdTegY4qi1