Research Experience for Undergraduates (REU)

 

 

CLASS of 2010
Student (click name for abstract)	Home university	Lab placement
Charles Majdalani	University of Texas at Austin	Bau group (MEAM)
Rosa Santana-Carrrero	University of Puerto Rico, Mayaguez	Daldal group (Biology)
Priya Balasubramanian	Duke University	Yang group (MSE)
Peter Forzaglia	Manhattan College	Lee group (CBE)
Adrian Levine	The University of Western Ontario	Tsourkas group (BE)
Stephanie Cheung	Grinnell College	Jouille group (Chemistry)
Jorrell Fredericks	Alabama State University	Johnson group (Physics)

 

This study demonstrates the ability to produce a portable, chemical heater that does not require electrical power.  The heater provides the temperature required for DNA amplification using the loop-mediated isothermal amplification (LAMP) reaction.  The heater is integrated into a chip containing LAMP reagents.  When saliva is injected into the chip, the heater will activate the process.  After completion, an indicator will display the diagnostic results.  The chip requires a flameless, chemical heater to heat the reagents to the optimal reaction temperature.  The components of this chip are inexpensive, making it viable for use in impoverished regions without access to diagnostic laboratories.  Currently, the chip research is directed towards rapid detection of the Human Immunodeficiency Virus (HIV).  In the future, the chip will be able to identify other diseases such as malaria.
 

The maturation process of c type cytochromes has been studied extensively in recent years and Cytochrome maturation system I (Ccm), one of the three proposed systems, consists of approximately 10 genes that encode membrane-bound components such as CcmI. This is a bipartite membrane protein in R. capsulatus, thought to be a chaperone of the apocytochrome c that forms a heme ligation core complex with CcmF and CcmH. The role of CcmI in the maturation of the cytochrome c₂ was analyzed by studying protein-protein interactions between CcmI and apocytochrome c₂.
 

A superhydrophobic surface is a phenomenon that can be characterized by the creation of a Cassie-Baxter wetting state indicated visually by high water repellency. The underlying mechanism to create a surface demonstrating the Cassie-Baxter wetting state is two-fold. The first mechanistic requirement necessitates roughness on the surface to allow for minimum contact of water with the surface. This requirement will be met through the self-assembly of silica nanoparticles on the substrate. The second mechanistic requirement is the use of a low surface energy material as a top surface coat to create chemically inherent water repellency. The presence of the Cassie-Baxter wetting state is measured through the contact angle of a five-microliter water droplet on the surface. A surface which has a static contact angle with a water droplet of 150 degrees or greater is labeled as a superhydrophobic surface. Through the application of functionalized silica nanoparticles to create dual scale roughness (two different sized nanoparticles coated as subsequent layers) followed by the deposition of a low surface energy coating on the surface of silicon wafers and fabric, the Cassie-Baxter wetting state was achieved. Two different varieties of functionalized nanoparticles were prepared and individually experimented with: aminopropyl-functionalized particles and fluorocarbon-functionalized particles. While the fluorocarbon-functionalized nanoparticles were hydrophobic by nature, the aminopropyl-functionalized nanoparticles necessitate a low surface energy top coating to allow for chemical hydrophobicity when fabricating the superhydrophobic surface. The cost-effectiveness and ease of coating the surface due to the silica particles, as well as the optical transparency that comes with the nano-scale roughness is beneficial in practical applications.

Layer-by-Layer assembly is a precisely tunable and versatile technique that can be used to form functional thin films. By varying the materials and assembly conditions, the range of functions of these films can also vary immensely. Mastery of this technique can have incredible implications in optics, biology, separations, and renewable energy. This research was conducted to find the optimal conditions for the assembly of TiO2 and carbon nanotube layers so that a composite film with photocatalytic properties can be formed. It was found that the addition of polymers (PSS and PEI) between the nanoparticle layers was critical for the adsorption of these particles. Salt-free solutions with a pH of 3 yielded the best results on the glass substrate for all attempted nanoparticle/polymer sequences. As a side project to the research, it was proven that LBL could not only be done in water, but also nonpolar solvents like toluene. This will widen the range of materials that can be assembled via LBL and make it even more valuable in even more fields.
 

The amine group on carbon 2 of glycol chitosan has an unusually low pKa, making it titratable at physiological pHs. This gives the polymer and its derivatives the potential to have pH dependent biological functions. However, to date, most functionalizations of glycol chitosan have been accomplished by reacting this amine group, resulting in the loss of this pH responsiveness. This paper delineates a facile protocol that allows for amination of the hydroxyl groups and conjugation of the created amine groups while the pH responsive amine group is protected with a pthalimide group.  This allows for the polymer to be functionalized with any amine reactive group while maintaining the original amine group, which is subsequently deprotected.
 

The trichodermamide family of natural products consists of three unique dipeptide compounds, trichodermamides A, B, and C, isolated from the marine-derived fungus Trichoderma virens. While trichodermamide A shows limited bioactivity, trichodermamides B and C show significant cytotoxicity against human colorectal carcinoma HCT-116 (IC₅₀ of 0.32mg/ml). Due to the biological significance and structural novelty of the trichodermamides, two total syntheses have been reported: a racemic total synthesis of trichodermamide B by the Zakarian group, and a enantioselective total synthesis of trichodermamides A and B by the Joullié group. Although the Joullié synthesis successfully synthesizes trichodermamides A and B, it contains problematic factors that could be improved upon. Moreover, a total synthesis of trichodermamide C is yet to be reported. Therefore, we are interested in developing a second generation total synthesis of trichodermamides A and B as well as the first total synthesis of trichodermamide C. Herein is described the proposed synthetic plan as well as the current progress of the second generation synthesis.
 

Carbon nanotubes, also known as CNTs, are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1. Since their discovery, carbon nanotubes (CNTs) have been widely studied due to their large potential applications. These cylindrical carbon molecules have novel properties that make them potentially useful in many applications in nanotechnology, electronics, optics and other fields of materials science as well as potential uses in architectural fields. They exhibit extraordinary strength and unique electrical properties, and are efficient thermal conductors. Nanotubes are categorized as single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs). First produced in arc-discharge process or by laser-ablation, the CNTs grown by catalytic chemical vapor deposition (CCVD) have been showing however a large expansion for the past decade. What is actually the role played by the catalyst in the CCVD of CNTs? In this paper, we will discuss the influence of the composition of the catalyst material, of the morphology of the catalyst nanoparticles, of the support, of the preparation method of the nanoparticles.
 

 

 

CLASS of 2009
Student (click name for abstract)	Home university	Lab placement
Yewande Alade	Swarthmore College	Robert Carpick
Oscar Beteta	Bucknell University	Daniel A. Hammer
Ninnette Jarenwattananon	Barnard College	Joshua Wand
Jennifer Kay	University of Pittsburgh	Daeyeon Lee
Derek Lee	Boston University	Jorge Santiago-Avilés
Abdul-Rahman O. Raji	Morgan State University	Christopher B. Murray
Lianette Rivera Baez	University of Puerto Rico, Mayaguez	Fevzi Daldal
Luis E. Reyes	Rowan University	So-Jung Park
Jonathan Rosen	Lehigh Univedrsity	Ju Li
Swarnali Sengupta	Johns Hopkins University	Robert L. Mauck
Laura Tanenbaum	Rice University	Kathleen Stebe
Marc J. van de Rijn	Stevens Institute of Technology	Beth Winkelstein
Jennifer Winkler	University of Rochester	Gianluca Piazza

 

CLASS of 2008
Student	Home university	Lab placement
Ian Clark	University of Oregon	Degrado Group
Orielyz Flores	University of Puerto Rico at Cayey	Santiago Group
Kendrick Hernandez	University of Puerto Rico-Mayaquez	Carpick Group
Matthew Kraeutler	University of Virginia	Composto Group
Brenna Krieger	Rutgers University	Goldman Group
Elliot Nelson	Wheaton College	Chen Group
Laurent Palmatier	University of California, San Diego	Bau Group
Frances Rodriguez	University of Puerto Rico at Cayey	Dmochowski Group
Swarnali Sengupta	Johns Hopkins University	Mauch Group
Serina Woods	Norfolk State University	Yodh Group
Livia Zarnescu	University of Arizona	Bonnell Group

 

Read details of former REU student participants

Class of 2007

Manpreet Sen, George Washington University
Manipulations of the Oxygen Scavenger System for Optimal Fluorophore Activity (read abstract)
worked in Yale Goldman’s group

Ricardo Rivera, University of Puerto Rico, Cayey
Fabrication of Oriented Polyethylene Oxide Microfibers Through Electrospinning (read abstract)
worked in Jorge Santiago-Aviles’ group

Kelisha Kuykendall, University of South Texas
Synthesis of Metal Polypyridyl Based Porphyrin Supermolecule for Non-Linear Optical Studies (read abstract)
worked in Michael Therien’s group

Kelly McCarthy, Pennsylvania State University
Synthesis, Characterization, and Assembly of CdSe Nanorods (read abstract)
worked in Marija Drndic’s group

Evan Reed, The College of New Jersey
FEM Modeling of Contour-Mode RF Piezoelectric Resonators (read abstract)
worked in Gianluca Piazza’s group

Arelys Rosado, University of Puerto Rico, Rio Piedras
Temperature Dependence of Domain Polarization on BaTiO3 Thin Film and Single Crystal (read abstract)
worked in Dawn Bonnell’s group

Class of 2006

Gloriell M. Cardona, Mathematics, University of Puerto Rico at Cayey
Study of the Use of Ferrofluid & Ferro-Wax as a Pumping & Valving Mechanism (read abstract)
worked in Haim Bau’s group

Tyson Moyer, Materials Science and Engineering, Cornell University
Forced Unfolding of Actinin Visualized in Embryonic Cardiomyocytes (read abstract)
worked in Dennis Discher’s group

Jessica Ortiz, Chemistry, University of Puerto Rico at Cayey
Crack Free PZT films by Sol-Gel Synthesis (read abstract)
worked in Dawn Bonnell’s group

Josean Paulino Sustache, Physics, University of Puerto Rico at Humacao
Electrostatic Deposition of Nanofibers for Gas Sensors (read abstract)
worked in Jorge Santiago-Aviles’ group

Diana Tomezsko, Chemistry, LaSalle University
Studies toward the Use of PPES and PNES Polymers to Dissolve and Separate Nanotubes (read abstract)
worked in Michael Therien’s group

During the summer of 2006, six students from across the country and Puerto Rico participate in the 10-week research program.  Their research is highlighted in the following sections.  
If you would like to participate in the Summer 2007 program, click here.

NBIC REU, Class of 2007

 

Porphyrins, a large class of deeply colored dyes, provide an interesting research opportunity because of their unique optical properties. Besides their biological significance, porphyrins have also been studied extensively from a materials scientific point of view. A unique class of supermolecular chromophore based on metal polypyridyl complexes and porphyrins have been developed in Therien lab. Completing the syntheses of these chromopores can be challenging. In this report the synthesis of RuPZn chromophore from commercially available reagents is discussed in detail.
 

Controlled alignment of semiconductor nanorods is desired for ongoing work involving individual nanorod luminescence, as well as transport measurements over an array of nanorods.  This paper documents the characterization of CdSe nanorods prepared by several methods of synthesis.  The concentration of solvents from which the nanorods are deposited on TEM grids has an effect on the assembly of nanorods before applying an electric field which has previously been found to influence the order within nanorod films, and to lead to nanorod alignment.  When dropcast on a carbon grid, a dilute solution of CdSe rods assemble relatively randomly, but showing small tracks about five rods.  However for a more concentrated solution of rods, multiple layers appear to form and track length increases to about fifty rods. An applied electric field during the drop-cast is expected to increase the order parameter further. 
 

Polyethylene oxide (PEO) fibers with sub-micron scale diameters were synthesized through electrospinning.  The fibers were deposited in a near-parallel arrangement through the use of a custom-made electrospinning apparatus consisting of a rotating target anode and a linearly translating syringe cathode.  The fibers exhibited diameters ranging from 0.7 microns to 55 microns, and were characterized using optical microscopy and surface-enhanced Raman spectroscopy (SERS).  In addition, PEO fibers containing silver nanoflakes (5 weight percent, mean diameter of 100nm) were synthesized and characterized in the same fashion.  In both cases, the diameters of the fibers varied only with changes in the rate at which the polymer solution was pumped to the syringe cathode.  Samples of both types of fibers were also sintered in a vacuum oven at 200°C for 30 minutes and 180°C for 10 minutes, and were characterized via the aforementioned techniques.  Although the sintered fibers exhibited enhanced signals during SERS, they also fluoresced more than the unsintered samples and were thus less amenable to this type of characterization.
 

Single molecule observations utilizing fluorescent probes are often plagued by short, intermittent light signals.  Fluorophores are essential to biological research, allowing researchers to observe molecular conformational changes and interactions with other molecules. Extended fluorophore lifetime is desirable and is currently achieved with the use of various anti-fade reagents. For each type of fluorescent probe different reagents were tested. Using the FIONA (Fluorescence Imaging with One Nanometer Accuracy) microscope, images of the fluorescent signals were captured under an assortment of conditions. Analysis of the images led to determination of the appropriate reagents and protocols for several types of fluorophores.

Note:  Ms Sen’s paper was recently published in journal of undergraduate research at The George Washington University called Inquiry, volume 5 (Spring 2008)

 

NBIC REU, Class of 2006

 

This research project is focused on studying the feasibility of using ferrofluid and ferro-wax as a pumping and valving mechanism in a microfluidic device.  The material used to create the chip was polycarbonate (PC).  Since it was found that controlling surface properties is necessary to create an effective pumping system, oxygen, and argon plasma treatment in addition to poly(vinyl pyrrolidone) or PVP solution application were used to make PC hydrophilic.  This is reflected by the water contact angle.  It decreased from ~ 45º to ~7º on all the treated samples.  In order to bond treated PC without reversing the plasma treatment, using a temperature less than 140 ºC, different bonding techniques using acetone and PVP were tested.  Dipping the PC in acetone and applying it using a pipe cleaner were the most effective techniques to use before using the thermal bonding press.  For future work, a further study of the use of ferro-wax as pump and valve is also necessary to determine at what parameter are these materials more effective.
 

α-Actinin is a member of the spectrin family and known primarily for cross-linking actin proteins.  It is involved in the formation of the cytoskeleton and connection to the plasma membrane.  The structure of α-Actinin is comprised of four spectrin repeats, EF-hands, and an actin-binding domain.  Previous research has shown that α-Actinin unfolds under force from Atomic Force Microscopy (AFM), which leads to the possibility of force-dependent change in cells.  The work described in this paper is a study designed to determine whether the unfolding of α-Actinin occurs under force from within embryonic cardiomyoctes through the exposure of a mutated cysteine inside the protein.  Using mutagenesis, cysteines in the spectrin repeats of α-Actinin are replaced by alanine, without any change to the structure.  Then, one cysteine is mutated into the protein at the inside of one of the three helices in the fourth spectrin repeat, so that a cysteine dye will not fluoresce under normal conditions.  By transfecting the mutated Actinin protein in chicken cardiomyocytes, the presence of a conformation change can be determined.  Under the forces in the beating cardiomyocytes, the α-Actinin undergoes forces strong enough to create a change in conformation.  The change in protein shape can be determined by causing any exposed cysteines to fluoresce, since the cysteine that was previously hidden will become exposed after the protein has unfolded.  Evidence that α-Actinin unfolds can show that it is involved in a force-sensitive pathway within the cell. 
 

Ferroelectric films are the materials of great technological importance.  These films could be used as a storage media (Fe-RAM, for example).  The other reason attractive application of those films is the study of domain specific reaction.  For these applications high quality ferroelectric films are required.  The most common ferroelectric material is Pb(Zr, Ti)O3, a.k.a. PZT. Many groups are synthesizing PZT but procedure varies from group to group as well as film quality (multiphase composition and grain size). In this work we found an optimal condition for the synthesis of crack free PbTiO3 films with grain size smaller then 1 mm.
 

This work addresses the formation of nanofibers of tin oxide (SnO₂) and carbon by using electrospinning aiming at application as gas sensors. The tin oxide (SnO₂) fibers were electrospun from a precursor solution containing 100 mg poly (ethylene oxide) (molecular weight 900 000), 10 ml chloroform (CHCl₃) and 5 ml dimethyldineodecanoate tin (C₂₂H₄₄O₄Sn). After the deposition, the fibers were sintered in a furnace for 1 h at 250, 320 and 600 ◦C, respectively. The scanning electron microscope was used to characterize the sintered fibers. After this analysis we studied the electrical conductivity of a single fiber. The carbon nanofibers used in this work were derived from a polyacrylonitrile (PAN)/N, N-dimethyl formamide (DMF) precursor solution using electrospinning and vacuum furnace techniques. The carbon fibers were observed in the optical microscope and photographed.
 

Single walled nanotubes (SWNTs) are carbon tubes with a wide range of novel thermal, mechanical, and opto-electrical properties that enable them to be such a functional material.  However, for any practical application of these properties, for example in the design of an electronic or optical device, a homogenous sample of SWNTs is needed.  When synthesized, SWNTs are a tangle of sizes, shapes, and chiralities.  In this project, new strategies for obtaining a homogenous sample of SWNTs are explored.
 

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