Updated: May 5, 2018
Currently, Safiya studies at Siena Heights University. She joined Professors Peng Zhang research team over the summer, working with his graduate student Emily Westbrook.
Her research was centered on probing the distance-dependence of surface-enhanced Raman Spectroscopy using nanocomposites composed of raman reference and probe conjugated copolymers grafted to gold nanoparticles.
Polymers are a large chain of monomers. Nanoparticles are microscopic materials that have a large surface area. Nanocomposites are made up of polymers and nanoparticles, which are used for instrumentation. One type of instrumentation that can be used is Surface-Enhanced Raman Spectroscopy (SERS); however criteria needs to be developed for future nanocomposite research. We grafted a series of block copolymers to gold nanoparticles to investigate the distance-dependence of SERS. The block copolymers were composed of Poly(Me methacrylate-glycidyl methacrylate) (PMMA-b-GMA). The copolymer series used an increasing amount of GMA (5-45 mol %) to determine the trend with the enhancement of SERS. It was detected that the enhancement of the probe signal was the greatest at the medium distance from the particle.
Take a look at Safiya explaing her experience in the REU program
Updated: May 5, 2018
Jacob is currently studying at University of Wyoming. He joined Professor Ruxandra Dima and her graduate student Dale Merz. Jacob was very succesful in his research and presented his work at the ACS meeting in New Orleans spring of 2018.
Jacob investigated allosteric mechanism of peptide release in the molecular chaperone Hsp70. In more details Hsp70 is a two-domain molecular chaperone involved in maintaining cellular homeostasis. Its function results from mech. changes caused by hydrolysis of ATP in the N-terminal nucleotide binding domain (NBD) that alter the client binding affinity of the C-terminal substrate binding domain (SBD). To study the dynamics of client binding, we linked the C-terminus of Hsp70 to a client peptide by means of an unstructured, chimeric linker. Utilizing coarse-grained simulations in concert with laser optical tweezer experimetns, we investigated the effects of force applied at various points of the linker on the unfolding of the SBD. Initial results indicate that stabilization varies across the SBD β-sandwich subdomain: the N-terminal β strands can detach before or after disruption of the rest of the subdomain.
Here is a link to a video of Jacob describing his experience at the end of the REU program
Updated: Jun 6, 2018
Ruth came from Fisk University to do research in collaboration with Professor Neil Ayers and his graduate student Qinyuan Chai. She presented her work at the ACS meeting elegantly spring of 2018.
Ruth’s project was part of a long-term study to investigate the effect of molecular weight on the effectiveness of a polymer anticoagulant. Our hypothesis has been that molecular weight, or the overall size of the polymer, should not have a marked effect on its anticoagulant ability. One example of a powerful naturally occurring polymer anticoagulant is heparin, which has been used as a blood thinner clinically for decades. Our lab has extensive experience in synthesizing and characterizing polymer anticoagulants that are effective at prolonging blood-clotting times. However, we have so far not been able to examine the effect of molecular weight as we have used a simple step-growth polymerization strategy. Ruth’s project was to prepare an amine-functionalized sugar (e.g. mannose or lactose) and use this to displace an activated ester on a polymer prepared by a controlled chain growth polymerization. The benefit of using a this controlled chain-growth derived polymer is that we can prepare polymer of multiple chain lengths but with narrow dispersities, i.e. all the chains have similar molecular weights within a sample. Therefore, upon achieving this synthesis we can accurately determine the effect of molecular weight on the anticoagulant ability of the polymer using our reported clotting time assays. Ruth was able to complete several steps of challenging organic chemistry in preparing the amine-functionalized sugars, and has positioned the project for future success. Ruth was able to gain skills in the synthesis and characterization of small molecules and experience in organic polymer chemistry during this project.
Here is a video of Ruth explaining what she gained from participating in the REU program.