UNC Programs

"Copper is a nutrient essential for life. Maintenance of copper balance within cells is key to preserving healthy biological function, with dysregulation of metal-related pathways leading to the development of disease states such as cancer and neurodegeneration.

The Ge Group studies how the proteins in our cells acquire, use, and transport metal ions including copper, and how chemical modifications of these proteins affect their structure and function. Undergraduate summer researchers will contribute to the semi-synthesis of modified copper-binding proteins by performing peptide synthesis, protein expression, and peptide/protein purification.

Anticipated student learning outcomes:
Technical skills and research experience: Students will gain hands-on experience with Fmoc-solid phase peptide synthesis, sterile technique, bacterial culture, protein expression and purification, as well as basic lab tasks such as preparing media and buffers. Professional skills: Students will also participate in lab meetings to discuss both literature and research topics to gain a better understanding of the process of scientific research.
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"The purpose of this project is to study the fluorescent properties and photochemistry of thiazolothiazole viologens for solar energy applications. In particular we will study the photoinduced electron transfer events from a donor chromophore to an acceptor thiazolothiazole viologen (TTz). We will monitor these dynamics by studying the fluorescence both of the donor and acceptor molecules.

Description
Figure 1. Electrochromism, fluorescence, and spectroelectrochemistry of thiazolothiazole.

Developing new methods to efficiently harvest solar energy and convert it into useable fuel is a great challenge of the 21st century. Using photocatalytic molecules to turn water and sunlight into valuable hydrogen “solar fuel” could enable solar energy to be stored and used on demand. The Walter research group has developed a new class of compounds that can be used to study photoinduced electron transfer events, using methods similar to those that utilize the electrochromic properties of methyl viologen. These thiazolothiazole viologen-like compounds show both electrochromism and strong fluorescence quenching after reduction. Using their unique properties, we can study the initial events that are critical for understanding light-induced catalytic events for the production of solar fuels. A variety of donor chromophore molecules will be studied such as porphyrins, ruthenium polypyridyl complexes, and phthalocyanines. The photophysics of thiazolothiazole compounds will be studied individually and as an acceptor species.
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"The purpose of this project is to develop novel multifunctional silica-based hybrid nanoparticles with properties for photodynamic therapy (PDT) and photodynamic inactivation (PDI) applications.

Description
Photodynamic therapy (PDT) is a light-based therapy that avoids most of the side effects of traditional chemical and radiation therapies. The principle of PDT is based on the selective internalization of a photosensitizer which upon irradiation with light generates reactive oxygen species that kill cancer cells. This approach can be expanded to eliminate antibiotic resistant bacteria, it is known as photodynamic inactivation (PDI). Traditionally, porphyrin-based photosensitizers have dominated the field; however, recent developments have shown that novel photosensitizing agents such as chlorin and phthalocyanine molecules are an excellent alternative. Nevertheless, these compounds still have similar disadvantages as porphyrin molecules such as low water solubility and reduced selectivity for targeted cancer cells. Nanoparticles represent emerging drug delivery systems that can overcome most of these issues. In this project, we will synthesize novel silica-based platforms including mesoporous silica nanoparticles (MSNs), polysilsesquioxane (PSilQ) and polyhedral oligomeric silsesquioxane (POSS) nanomaterials for the improved delivery of photosensitizing agents. The therapeutic properties of the silica-based hybrid nanoparticles will be tested in vitro using cancer cells and/or antibiotic resistant bacteria.
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"The purpose of this project is to develop novel applications of LETs in photonic integrated circuits (PICs).

Description
LETs are photo-conductive devices with suitable characteristics that can mimic the functionalities of FETs (field-effect transistors) but instead using light to modify the conductivity of the channel. LETs can potentially offer advantages over FETs in switching speed and switching energy. Furthermore, LETs provide unique functions that not available from FETs, for instance, multiple-beam gating, which allows for the realization of OR and AND logic function with a single LET, in turn, new and simplified circuit designs. This project will use LETs to construct an XOR gate that is the key component of a half adder or full adder in computing applications.
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"The purpose of this project is to computationally design nanomaterials to control the flow of light and heat for energy applications.

Description
Designing materials on the nanoscale can have a profound impact on how optical energy flows through those materials, which can in turn dramatically improve the performance of nanostructured materials for energy-related applications including solar and (solar)thermophotovoltaic energy conversion, radiative cooling, incandescent lighting, among others. Multilayer nanostructures represent an important class of materials with tunable optical and thermal radiative properties that can be leveraged for a wide range of energy applications. We have developed an open-source software package called WPTherml that couples rigorous electrodynamics computations to thermal radiation equations and aims to provide a powerful computational design engine for multilayer nanostructures for applications where control of optical and/or thermal radiation properties are paramount. This software tool will be used to explore novel energy applications, and to design materials that can advance those applications.

Figure 1. Reshaping the solar spectrum with spectrally-selective thermal emitters
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"The goal of this project is to synthesize, characterize, and study the properties of new silicon pincer compounds to enable more efficient organic electronic devices. 

Research mentors
Tom Schmedake (CHEM) and Daniel Rabinovich (CHEM)

Description
Researchers in the Schmedake lab have synthesized a variety of hexacoordinate silicon-based complexes for electronic applications, including organic light emitting diodes (OLEDs) and organic photovoltaics OPVs. We focus on complexes that contain pincer ligands such as the 2,6-(bis-benzamidazol-2-yl)pyridine, bzimpy ligand (Figure 1) due to the advantageous properties this molecular motif provides, including high glass transition temperatures, excellent stability, and high charge mobility. This summer REU students will synthesize new  hexacoordinate silicon complexes for OLED lighting applications."
"The goal of this project is to synthesize one-dimensional (1D) oxide nanostructures using chemical vapor deposition (CVD) and study their plasmonic properties for plasmon enhanced photocatalytic applications.

Research Mentors
Haitao Zhang (Mechanical Engineering and Engineering Science)

Description
Metalloids are a group of elemental materials with properties in between those of metals and nonmetals, including B, Si, Ge, As, Te, and At, etc. While various nanostructures of B, Si, and Ge have been intensively studied with synthesis, property measurement and device testing, the nanostructures of other metalloids have not been thoroughly investigated. We are interested in the nanostructures of Te (tellurium). Te is a p-type semiconductor with a narrow band gap, which can be tuned with dimension control. It has special electrical and optical properties, such as photoconductivity, non-linear optical property, high carrier mobility, thermoelectricity, and piezoelectricity, etc. This talk is focused on the development of low-dimensional structures of Te, from microrods, nanowires, to nanoplates using a vapor-based synthesis method. Growth mechanism study is performed to explore the parameter effects on the growth control of dimensions and morphologies. Structure characterization and photoconductivity property measurement are also performed."
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The main goal of this project is to use synthetic molecular clusters as building blocks to
assemble a new class of multi-dimensional coordination solids.

Description
We will design and synthesize framework materials comprised of metal sulfur clusters crosslinked by organic ligands. Synthetic analogues to traditional transition metal dichalcogenides (TMDC) using molecular precursors are needed to prepare functional materials by design. Incorporating nanometer sized clusters, into high surface area frameworks will allow for rational modification and new materials with applications in nanoelectronics, optoelectronics, and catalysis. We have recently prepared amorphous, low surface area materials from Co4S4 clusters and bis-N-heterecyclic carbene (NHC) linkers. This project will focus on strategies to enhance crystallinity in second generation polymers."
"The goal of this project is to investigate new designing principles for engineering programmable RNA nanoassemblies that can be activated in response to various stimuli and have controllable immunological properties.

Description
The emerging field of RNA nanotechnology comprises general knowledge of RNA structures, functions of various natural and artificial classes of RNAs, and their roles in different diseases to tackle specific biomedical and nanotechnological problems. It becomes evident that building functional RNA-based nanomaterials that can either (a) communicate with each other or with cellular machinery or (b) be readily responsive to various stimuli, can improve the operation of current therapeutic systems and allow the engineering of novel “smart” biomaterials. The overall goal of this project is to obtain a fundamental understanding of the relationship between nanostructure in RNA-based nanoassemblies, their immunological properties, and their responsiveness to external stimuli, which will enable the design and characterization of a new class of nanostructured materials with programmable stimuli-responsive reconfigurable properties and conditional activation of the immune responses."
"Despite the existing variety of RNA (and DNA) nanoparticles (NPs) and computational tools for their design, the use of RNA NPs as modular building blocks for constructing RNA networks has never been systematically investigated. To address this need and thereby shift the existing paradigm, the goal of this project is to develop an RNA-based, programmable networking platform that simultaneously encodes targeted biophysical, mechanical, and biochemical properties through networks with multiple independently programmable architectural parameters.

Description
The functionally-versatile RNA plays an essential role in living systems, and the new discipline of RNA nanotechnology studies how this intriguing biopolymer can be programmed to assemble into defined shapes and sizes with varying physicochemical and biological properties. These novel design principles address some fundamental problems relevant to the RNA structure-activity relationship, biophysics of folding, and chemical interactions with other biomolecules. They also allow RNA nanoparticles to be designed for applications in biosensors, circuits, and therapeutics. To advance current designs, this project seeks to incorporate multiple RNA nanoparticles into assembled networks in order to elucidate the critical parameters of this bottom-up assembly. By characterizing the physicochemical, mechanical, and biochemical properties of RNA networks, the results of this work will enable the establishment of assemblies with desired properties based upon the types of nanoparticles incorporated and their linking moieties."