This project will explore the use of quantum dots with built-in spontaneous polarizations and infrared-excited quantum dots in switching voltage-gated ion channels. Specifically, this project will study the interaction of the dipole fields produced by the built-in spontaneous polarization as well as by the radiation-induced polarization of quantum dots with ion channels that are gated with voltages. This research will include STM/AFM characterization of semiconductor quantum dots under illumination and of semiconductor quantum dots that have built-in spontaneous polarizations in the absence of external radiation; results will be compared with modeled characteristics. Patch clamp techniques will be used to measure the response of voltage-gated ion channels to these quantum-dot fields for a variety of scenarios including: (A) the switching of ion channels with infrared-excited quantum dots that are bound directly to ion channels with molecular linkers, and (B) the switching of ion channels for the case where quantum dots having large built-in spontaneous polarizations, that produce large electric fields surrounding the quantum dots, are bound directly to ion channels by molecular linkers. This project will conduct proof-of-principle research underlying the excitation of quantum dots with tissue-penetrating infrared radiation for the subsequent active control of ion channels as well as the static gating of ion channels using quantum dots that have built-in spontaneous polarizations in the absence of external illumination.
Broader Impact: The broader impacts of this program are numerous and they underlie the exploitation of novel nanosystems that will perform functions - not now performed with current devices and systems that will have impact on economic, medical, and scientific issues, as well as the education of new generations of students in emerging techniques that will have broad and continuing payoffs in a variety of scientific, medical, technological, and economic applications. In particular, this project underlies the novel use manmade colloidal quantum-dot nanosystems consisting of semiconductor colloidal quantum dots to influence the functions of biological ion channels. The success of this program would advance the application of nanotechnology to the beneficial control and modification of ion channel functions. As specific examples of impact, this program will explore novel approaches for using colloidal quantum dots for switching ion channels that have potential for long-term practical applications including: (A) the control of neural functions and response; (B) advanced prosthetics and; (C) the design of novel manmade nanostructures that perform channel blocking functions similar to those of many drugs employed in the neurological and cardiac applications.
