A5007636230- Conducting polymers and applications
- Analytical Chemistry and Sensors
- Advanced biosensing and bioanalysis techniques
- Organic Electronics and Photovoltaics
- DNA and Nucleic Acid Chemistry
- Electrochemical Analysis and Applications
- Gas Sensing Nanomaterials and Sensors
- RNA Interference and Gene Delivery
- Electrochemical sensors and biosensors
- Photochromic and Fluorescence Chemistry
- Perovskite Materials and Applications
- Click Chemistry and Applications
- Supramolecular Self-Assembly in Materials
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Molecular Junctions and Nanostructures
- Thermal properties of materials
- CO2 Reduction Techniques and Catalysts
- Semiconductor Lasers and Optical Devices
- Advanced Thermoelectric Materials and Devices
- Advanced Polymer Synthesis and Characterization
- Covalent Organic Framework Applications
- Polyoxometalates: Synthesis and Applications
- Catalytic Processes in Materials Science
- Metal-Organic Frameworks: Synthesis and Applications
Georgia Institute of Technology
2007-2025
Johns Hopkins University
1988-2023
University of Baltimore
2020
University of Maryland, Baltimore County
2019
University of Colorado Boulder
2015-2018
Co-delivery of both chemotherapy drugs and siRNA from a single delivery vehicle can have significant impact on cancer therapy due to the potential for overcoming issues such as drug resistance. However, inherent chemical differences between charged nucleic acids hydrophobic hindered entrapment components within carrier. While poly(ethylene glycol)-block-poly(lactic-co-glycolic acid) (PEG-PLGA) copolymers been used successfully targeted drugs, loading DNA or RNA has poor. It is demonstrated...
Abstract Synthetic polymer approaches generally lack the ability to control primary sequence, with sequence referred as holy grail. Two click chemistry reactions were now combined form nucleobase‐containing sequence‐controlled polymers in simple polymerization reactions. distinct are used these nucleic acid (CNA) polymers. These employ thiol–ene and thiol‐Michael homopolymers of a single nucleobase (e.g., poly(A) n ) or specific repeating sequences poly(ATC) ). Furthermore, incorporation...
Metal alloys with atomic scale ordering (ordered intermetallics) have emerged as a new class of high performance materials for mediating electrochemical reactions. However, ordered intermetallic nanostructures often require long synthesis times and/or temperature annealing to form because high-activation energy barrier interdiffusion must be overcome the constituent metals equilibrate into structures. Here we report direct metastable Pd31Bi12 at room-temperature in minutes via deposition. is...
The development of high-performance-conjugated polymer-based gas sensors involves detailed structural tailoring such that high sensitivities are achieved without compromising the stability fabricated devices. In this work, we systematically developed a series diketopyrrolopyrrole (DPP)-based polymer semiconductors by modifying backbone to achieve and rationalize enhancements in electronic air. NO2- NH3-responsive organic field-effect transistors (OFETs) described with improved air compared...
Spontaneous chiral symmetry breaking remains a fascination in chemistry, biology, materials science, and even astronomy. Chiral usually requires intrinsic molecular chirality or extrinsic sources but rare non-chiral systems. Here, we reveal ubiquitous, entropy-driven mechanism observed 22 out of 35 conjugated polymers the absence any source – phenomenon overlooked for decades. assemblies spontaneously occur through liquid-liquid phase separation (LLPS) lyotropic mesophases from isotropic...
A carboxylated thiophene polymer-based chemiresistive device in a field-effect transistor (FET) configuration with unusual and enhanced responses to the widespread pollutants nitrogen dioxide (NO<sub>2</sub>) ammonia (NH<sub>3</sub>) is described.
Characterizing doping effects in a conductive polymer and physical diffusion passive were performed using remote-gate field-effect transistor (RG FET) detection system that was able to measure the electrical potential perturbation of film coupled gate silicon FET. Poly(3-hexylthiophene) (P3HT) doped various concentrations 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) solutions imposed additional positive potentials on P3HT RG, resulting lower threshold voltage (Vth) n-channel...
In this work, we have designed a series of anodically coloring electrochromic (ACE) molecules comprised thioalkyl-substituted 3,4-ethylenedioxythiophenes coupled to triphenylamine units (EDOT-TPA) that vary in the position and degree electron richness substituents, which influences geometric, electrochemical, optoelectronic, excited-state properties. We evaluated their redox properties discovered modulation both first second oxidation potential, formation cation radical dication, can be...
Coordination polymers (CPs) supporting tunable through-framework conduction and responsive properties are of significant interest for enabling a new generation active devices. However, such architectures rare. We report redox-active CP composed two-dimensional (2D) lattices coordinatively bonded Mo2(INA)4 clusters (INA = isonicotinate). The 2D commensurately stacked their ordering topology can be synthetically tuned. material has hierarchical pore structure (pore sizes distributed between 7...
Abstract The design of polymeric semiconductors exhibiting high electrical conductivity (σ) and thermoelectric power factor (PF) will be vital for flexible large‐area electronics. In this work, four polymers based on diketopyrrolopyrrole (DPP), 2,3‐dihydrothieno[3,4‐b][1,4]dioxine (EDOT), thieno[3,2‐b]thiophene (TT), 3, 3′‐bis (2‐(2‐(2‐methoxyethoxy) ethoxy) ethoxy)‐2, 2′‐bithiophene (MEET) are investigated as side‐chains, with the MEET newly synthesized study. These systematically doped...
We investigated the carboxylated conjugated polymer poly 3-(3-carboxypropyl)thiophene-2,5-diyl as a nanosized (200–350 nm) biomolecule receptor layer on channel of organic electrochemical transistor (OECT) devices. Myelin basic protein, SARS-CoV-2 spike glycoprotein S1, and their antibodies (10 nm size scale) were alternately used in attached molecule form receptors analytes. Sub-ng detection buffer was observed, response to S1 also obtained clinical serum. Changes threshold voltage current...
This work assesses the steric, torsional, and electronic effects of substituents on anodically coloring electrochromic (ACE) molecules to gain insight toward constructing highly transmissive neutral states, while attaining vibrant colors in their cation radical dication states. We examine seven thioalkyl-substituted bis(3,4-ethylenedioxthiophene)-1,4-phenylene (BEDOT-Ph) ACE compare optoelectronic, geometric, excited-state properties. evaluate redox properties show that first oxidation...
The design concept for a subcritical, He-cooled, fast reactor, fueled with transuranics (TRUs) from spent nuclear fuel in coated TRISO particles and driven by tokamak D-T fusion neutron source, is being developed at Georgia Institute of Technology. basic has been two previous papers. This paper reports (a) advances the intended to enable achievement “deep-burn” TRUs passive safety, (b) investigations possibility reprocessing TRU extending strength (c) more extensive analyses confirm improve...
Abstract Polythiophenes with differently functionalized side chains (alkyl, oligoethylene oxide, ester, hydroxy, and carboxylic acid) varied counter ions of potassium salt electrolytes were investigated in organic electrochemical transistors (OECTs). In addition, mixed blends to evaluate any synergistic effects between functionalities. Depending on the functional moiety attached, a large shift lower potentials V th , an increase drain current, transconductance can be observed compared base...
Thiophene copolymers (representative structures shown) gave enhanced, uncorrelated response to NO 2 , NH 3 and acetone vapors. Linear discriminant analysis of responses thirteen polymers correctly classified groups as arising from individual
Abstract Synthetic polymer approaches generally lack the ability to control primary sequence, with sequence referred as holy grail. Two click chemistry reactions were now combined form nucleobase‐containing sequence‐controlled polymers in simple polymerization reactions. distinct are used these nucleic acid (CNA) polymers. These employ thiol–ene and thiol‐Michael homopolymers of a single nucleobase (e.g., poly(A) n ) or specific repeating sequences poly(ATC) ). Furthermore, incorporation...
The recently developed synthetic oligonucleotides referred to as "click" nucleic acids (CNAs) are promising due their relatively simple synthesis based on thiol–X reactions with numerous potential applications in biotechnology, biodetection, gene silencing, and drug delivery. Here, the cytocompatibility cellular uptake of rhodamine tagged, PEGylated CNA copolymers (PEG-CNA-RHO) were evaluated. NIH 3T3 fibroblast cells treated for 1 h 1, 10, or 100 μg/mL PEG-CNA-RHO maintained an average cell...
Abstract A systematic analysis is used to understand electrical drift occurring in field‐effect transistor (FET) dissolved‐analyte sensors by investigating its dependence on electrode surface‐solution combinations a remote‐gate (RG) FET configuration. Water at pH 7 and neat acetonitrile, having different dipoles polarizabilities, are applied the RG surface of indium tin oxide, SiO 2 , hexamethyldisilazane‐modified polystyrene, poly(styrene‐ co ‐acrylic acid), poly(3‐hexylthiophene‐2,5‐diyl)...
Ionic doping effects in conjugated polymers often cause nonspecific signaling and a low selectivity of bioelectronic sensing. Using remote-gate field-effect transistor characterization molecular ionic poly(3-hexylthiophene) (P3HT) acid-functionalized polythiophene, poly[3-(3-carboxypropyl) thiophene-2,5-diyl] (PT-COOH), we discovered that proton on the interfacial potential occurring P3HT could be suppressed by sequentially 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ). To...
We demonstrated the use of as-received conjugated polymer P3HT [poly (3-hexylthiophene-2,5 diyl)] doped with F4TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) as a matrix for forming composite as-received, commercially available p-type Bi2Te3 powder. The optimized formulation exhibits power factor up to 5.3μWK−2m−1, about nine times higher than highest that we achieved from mixtures only and F4TCNQ. was responsible increases in both Seebeck coefficient electrical conductivity....
To meet the growing demand for accurate, rapid, and cost-effective at-home clinical testing, we developed a radical-mediated enzyme assay (REEA) integrated with paper fluidic system electrically read by handheld field-effect transistor (FET) device. The REEA utilizes horseradish peroxidase (HRP) to catalyze conversion of aromatic substrates into radical forms, producing protons detected an ion-sensitive FET biomarker quantification. Through screening 14 phenolic compounds, halogenated...
Abstract The sensing properties of poly 3‐(3‐carboxypropyl) thiophene‐2,5‐diyl (PT‐COOH) and hydroxylated polythiophene (PT‐OH) as bioreceptor layers were studied are discussed in this paper. polymer films cover the channel region OECT devices anti‐human IgG was immobilized on films. We use threshold voltage (Vth) change a signal to detect interaction between human IgG. By adding different concentrations IgG, Vth difference can be observed films, with optimized detection from blend two...
Alkylthiophene polymers with unique and differing terminally functionalized side chains were investigated by using a vapor analyte/dopant, nitrogen dioxide (NO2), the thermoelectric properties examined. We observed that through NO2 absorption on or in sample induced charge carrier generation transport, conductivities of regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT), poly[3-(ethyl-4-butoanote)thiophene-2,5-diyl] (PT-COOR), poly[3-(3-caboxypropyl)thiophene-2,5-diyl] (PT-COOH),...