Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Session: 1
Room: Exhibit Hall
Timmy Bao Nguyen - California State Polytechnic University, Pomona
Co-Author(s): Casey L. Wouters, University of Minnesota - Twin Cities, Minneapolis, MN; Clare E. Froehlich, University of Minnesota - Twin Cities, Minneapolis, MN
Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical technique used in the field of biosensing for the detection of single molecules or entities, such as viruses. SERS is dependent on the exploitation of the electromagnetic enhancement induced by excitation of the localized surface plasmon resonance (LSPR). We explored the synthesis of alternative LSPR-supporting substrate platforms to develop an optimal SERS detection scheme for viruses. Metal film over nanospheres (FON) substrates and nanoparticle colloids were synthesized as potential SERS substrates to be used with the polymer affinity agent, poly(2-hydroxyethyl methacrylate) (pHEMA). Each substrate’s viability was evaluated based on its LSPR, nanoscale surface roughness, and pHEMA SERS signals. To achieve maximum enhancement, we tuned the substrates’ LSPR by altering the method and thickness of the gold deposition. When comparing the FONs substrates, those coated using an electron beam deposition produced a more red-shifted LSPR, higher nanoroughness, and stronger polymer Raman peak intensity than the substrates coated with a sputter deposition. Gold nanosphere and nanostar colloids were also synthesized as potential SERS substrates, but both overall performed less well than the FONs. We will continue optimizing the LSPR and conduct virus detection studies with the best performing SERS substrates.
Funder Acknowledgement(s): Boehringer IngelheimNSF
Faculty Advisor: Christy Haynes, chaynes@umn.edu
Role: I was in charge of preparing the substrates for gold deposition by dropcasting silica nanospheres onto the substrates, obtaining LSPR measurements of the gold-coated substrates using UV-Vis, incubating pHEMA polymer on the substrates, obtaining the Raman spectra, and analyzing the data produced by the substrates. Similarly, I generated colloid samples and assisted in the incubation and measurement of the Raman spectra. After initially shadowing my mentor, I was able to develop my own conditions by tuning the parameters in incubation time to independently collect data on the substrates.