Rebeca Rodriguez receives WCC Merck Research Award
Rebeca "Becky" Rodriguez, a 4th-year graduate student working with Professor Christy Haynes, has received the prestigious and competitive Women Chemists Committee (WCC)/Merck Research Award, which recognizes research excellence.
Eight female chemists in their third or fourth year of graduate school were chosen to receive this award and present their research at the 2020 WCC Merck Research Awards Symposium at the fall American Chemical Society national meeting, from 8:25 a.m. to 12:05 p.m. Sunday, Aug. 16. Becky will be speaking at 11 a.m. To attend and receive the link, send your name, email and affiliation to strongdespina@gmail.com.
Becky's research is at the interface of analytical, polymer, and materials chemistry. She is working to create inexpensive sensors for biological target detection. Using a polymer affinity agent, which is less specific than traditional affinity agents, provides the potential for multiplex detection, the ability to detect more than one target simultaneously.
The abstract for her presentation, "Optimizing inear polymer affinity agents for SERS Detection of aflatoxin B1," is: "Linear polymer affinity agents serve as a strong potential to detect multiple targets at once, with various analytical techniques. To study how to best optimize the use of these affinity agents, a series of poly(N-acryloyl glycinamide) (pNAGA) polymers were synthesized and studied as capture agents for surface-enhanced Raman scattering (SERS) detection of aflatoxin B1 (AFB1), a highly carcinogenic food-borne toxin. Four molecular weights of pNAGA were synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization to study the dependence of affinity agent efficacy on chain length for this AFB1 sensing platform. Isothermal titration calorimetry (ITC) was used to verify the sign and magnitude of the enthalpic effects involved in polymer–AFB1 interactions in solution and to understand the effects of pNAGA chain length on AFB1 noncovalent binding. pNAGA–AFB1 interactions were found to be exothermic, and longer pNAGA chains generally resulted in smaller enthalpy decreases per repeat unit. With pNAGA22 being thermodynamically the strongest affinity agent, we hypothesize that AFB1 affinity is determined by a balance between the configurational restrictions in pNAGA chains and the enthalpic advantage of binding AFB1. SERS spectral changes observed following AFB1 exposure were used to evaluate the influence of polymer molecular weight, order of attachment (pre- vs. post- functionalization of the substrate) and attachment chemistry (thiol vs. trithiocarbonate) on the sensitivity of AFB1 detection. The method by which target, polymer affinity agent, and signal transduction mechanism are combined was found to have significant impacts on the achieved sensitivity. The most effective polymer chain length (pNAGA22), anchoring chemistry (thiol), and polymer/toxin assembly scheme (in-solution) allowed detection of 10 ppb AFB1 in water (below the FDA regulatory limit of 20 ppb), a hundred-fold improvement over SERS sensing without the pNAGA affinity agent."
Becky's co-authors are Victoria M. Szlag, Theresa M. Reineke, and Christy L. Haynes.