Coronary heart disease, which leads to heart attack, is the most common type of heart disease killing 380,000 people annually. It has been widely accepted that a specific molecule, the cardiac troponin I, in blood serves as a highly sensitive and specific indicator for the detection of heart attack. While there are numerous commerically available bioassays available to detect this molecule with requisite sensitivity and specificity, these tests are time consuming and require specially trained personnel. This project seeks to create a novel class of sensors which can detect cardiac troponin I with high sensitivity and extreme selectivity in resource-limited settings. The long-term impact of the proposed work is to shorten the time between the occurrence and the determination of a heart attack such that appropriate treatment can be administered rapidly thus saving lives and improving patient quality of life. The proposal will focus on hiring women and minority graduate students for conducting the above research. Opportunities for undergraduate students to conduct summer research will be provided. The project will also provide opportunities for high-school students, especially those from underrepresented groups, to participate in the micro- and nano-fabrication summer camps in the university cleanroom. The experiential learning-based science activities will directly help these high school students to prepare for colleges and improve their chances of pursuing professional STEM education.
This project will exploit the conversion of an optical signal into an electrical output on a device platform to detect the cardiac biomarker, the cardiac troponin I, with high sensitivity and specificity. The device will consist of gold nanoparticles covered with a semiconducting film and contacted by two electrodes. The conductance of the illuminated device will be determined by plasmonically induced, energetic hot electrons generated in gold nanoparticles and subsequently injected into the semiconducting film. In turn, the gold nanoparticles will be functionalized to specifically capture the target biomarker associated with heart attack. Upon cardiac troponin I binding, changes to the immediate dielectric environment will result in a shift in localized surface plasmon resonance wavelength of the gold nanoparticles. This will result in the reduction of plasmonically generated hot electron injection and hence lower the conductivity of the illuminated device. Therefore, the quantifiable loss in photoconductivity will signal the presence and concentration of the biomarker, the cardiac troponin I, for detecting heart attack.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
