The reversible Lower Critical Solution Temperature (LCST) response of Elastin-Like Polymers (ELP) has been investigated. It is well known that the coacervation versus solubility of ELPs in solution can be triggered by different factors including ionic strength and temperature. Recently our group studied the electrochemical impedance spectroscopy (EIS) response of ELP-modified surfaces associated with changes in ionic strength, and we observed intermediate states of ELP surface collapse.¹

Within this work, we present our progress on monitoring the thermal response of surface-bound ELP. We will examine the localized temperature-triggered collapse for a (VPGIG)₄₀ ELP (with a cysteine near the N terminus) with EIS to better understand the way charge transfer changes within a range of temperature and intermediate states. We studied two surfaces, (1) carboxyphenyl-modified glassy carbon electrode modified with ELP via EDC/NHS bioconjugation chemistry and (2) gold electrode thiol-bonded ELP surfaces. We will report on observed changes in charge transfer resistance from 5 to 40 degrees Celsius.

[1] Morales, M.A., Paiva, W.A., Marvin, L., Balog, E.R.M. and Halpern, J.M., 2019. Electrochemical characterization of the stimuli-response of surface-immobilized elastin-like polymers. Soft matter, 15(47), pp.9640-9646.