Grant: Research Tools and Instruments

The requested instrumentation is for two technologies, Raman spectroscopy and electrochemistry, which we will combine as a single research platform. Raman uses a laser to provide a unique signal for every type of molecule based on molecular vibrations. This "vibrational fingerprint" allows easy identification of a sample, but the downside of Raman is that its signal is weak for low concentration samples. This problem is solved by a method called surface-enhanced Raman spectroscopy (SERS), which typically boosts the signal by at least a million-fold and often more. SERS occurs when the analyte molecule is on or near or gold or silver nanoparticles (NPs) and the laser is focussed on them. Concentrated NP paste is often dried on a surface, and the NPs can be modified to capture a target molecule. The signal boost in SERS makes it a popular technique for scientists and engineers who research new ways to diagnose diseases with low concentration biomarkers. A less commonly researched variation of SERS is called electrochemical SERS (EC-SERS). In this method, the NPs are dried on an electrode, it is exposed to an analyte, immersed in an electrolyte solution, and then a voltage is applied while recording SERS. EC-SERS has many benefits, including boosting the signal even more than traditional SERS and controlling how molecules interact with the NPs. For example, a positively charged molecule could be brought closer to a negatively charged surface. This is important because all SERS signals require the molecule to be very close to the NPs (10 nm or less). As another example, unwanted molecules that interfere with the signal can be removed from the surface. A classic case is negatively charged citrate, which is left over from making NPs and stuck on their surface. It is best to remove the citrate, as it creates an interfering signal. I am requesting funding for an EC-SERS platform. I am a new assistant professor and early career researcher with expertise in EC-SERS, but we do not have the instruments. With them, I can drive innovation and train the next generation of scientists with expertise in healthcare diagnostics. My research goal is to develop the EC-SERS platform for early disease detection. We will start with the fundamentals of this underexplored technology, but as practical examples, we will work on detecting molecules that provide early warning for prostate and ovarian cancers. My other area of research expertise is DNA nanotechnology, which can use specially designed DNA to capture target molecules. By chemically modifying NPs with DNA and drying them on a disposable material, we will use EC-SERS to detect molecules found in urine that can help with earlier diagnosis of these cancers. Research students trained on EC-SERS will gain highly employable skills in spectroscopy, electrochemistry, nanomaterials, DNA chemistry, safety using biofluids and lasers, and experience in clinical collaboration, all in the context of making a biomedical device.