The goal of this project is to increase the number of underrepresented minorities participating in biomedical and behavioral research. In that regard, this project will focus on the development of new biosensors based on enzymes adsorbed on carbon nanotubes, and then demonstrate the capabilities of such biosensors by integrating them in capillary electrophoresis microchips. Carbon nanotubes (CNT) display excellent qualities toward electrochemical biosensors. CNT are biocompatible, are stable over a large range of potentials, demonstrate catalytic activities toward many electrochemical reactions, and provide a significant increase in electrode area. Although considerable progress has been made by encapsulating or cross-linking enzymes, the analytical performance of CNT-biosensors still suffers from some fundamental deficiencies such as slow response (>10 sec) and limited sensitivity (~micro-M). The proposed biosensors will have larger and faster response than standard biosensors and will combine the selectivity of enzymes, the catalytic activity and conductivity of carbon nanotubes with the sample handling capabilities and separation means of capillary electrophoresis microchips. The hypothesis of this project is that experimental conditions can be rationally selected to maximize the adsorption of enzymes to carbon nanotubes, while preserving the enzymatic activity. Since the conditions used for the adsorption have a central effect on the enzymatic conformation and activity, we will first investigate how different enzymes interact with carbon nanotubes. By analyzing the adsorption kinetics under different conditions we will establish a rational link between enzyme properties and adsorption conditions. Then, we will demonstrate the advantages of coupling these biosensors to a capillary electrophoresis microchip. We expect to avoid harsh binding conditions (enzyme-electrode), minimize the response time, maximize the signal magnitude, and decrease the peak tailing associated with membranes (applied to trap the enzyme). Since the proposed sensor will be integrated with a capillary electrophoresis microchip, operations such as sample pretreatment, injection, and separation can be included and automated. We will study how enzymes interact with carbon nanotubes. Then, we will apply that information to develop sensors to monitor important molecules and diagnose diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Continuance Award (SC3)
Project #
5SC3GM081085-04
Application #
7908843
Study Section
Special Emphasis Panel (ZGM1-MBRS-1 (SC))
Program Officer
Gindhart, Joseph G
Project Start
2007-09-01
Project End
2011-12-31
Budget Start
2010-09-01
Budget End
2011-12-31
Support Year
4
Fiscal Year
2010
Total Cost
$106,125
Indirect Cost
Name
University of Texas Health Science Center San Antonio
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
800189185
City
San Antonio
State
TX
Country
United States
Zip Code
78249
Giuliani, Jason G; Benavidez, Tomás E; Duran, Gema M et al. (2016) Development and Characterization of Carbon Based Electrodes from Pyrolyzed Paper for Biosensing Applications. J Electroanal Chem (Lausanne) 765:8-15
Benavidez, Tomás E; Wechsler, Marissa E; Farrer, Madeleine M et al. (2016) Electrochemically Preadsorbed Collagen Promotes Adult Human Mesenchymal Stem Cell Adhesion. Tissue Eng Part C Methods 22:69-75
Durán, Gema M; Benavidez, Tomás E; Ríos, Ángel et al. (2016) Quantum Dot-Modified Paper-Based Assay for Glucose Screening. Mikrochim Acta 183:611-616
Benavidez, Tomás E; Torrente, Daniel; Marucho, Marcelo et al. (2015) Adsorption of soft and hard proteins onto OTCEs under the influence of an external electric field. Langmuir 31:2455-62
Bhakta, Samir A; Evans, Elizabeth; Benavidez, Tomás E et al. (2015) Protein adsorption onto nanomaterials for the development of biosensors and analytical devices: a review. Anal Chim Acta 872:7-25
Evans, Elizabeth; Gabriel, Ellen Flávia Moreira; Benavidez, Tomás E et al. (2014) Modification of microfluidic paper-based devices with silica nanoparticles. Analyst 139:5560-7
Bhakta, Samir A; Benavidez, Tomas E; Garcia, Carlos D (2014) Immobilization of glucose oxidase to nanostructured films of polystyrene-block-poly(2-vinylpyridine). J Colloid Interface Sci 430:351-6
Benavidez, Tomás E; Torrente, Daniel; Marucho, Marcelo et al. (2014) Adsorption and catalytic activity of glucose oxidase accumulated on OTCE upon the application of external potential. J Colloid Interface Sci 435:164-70
Moreira Gabriel, Ellen Flávia; Tomazelli Coltro, Wendell Karlos; Garcia, Carlos D (2014) Fast and versatile fabrication of PMMA microchip electrophoretic devices by laser engraving. Electrophoresis 35:2325-32
Felhofer, Jessica L; Scida, Karen; Penick, Mark et al. (2013) Simultaneous solid phase extraction and derivatization of aliphatic primary amines prior to separation and UV-absorbance detection. Talanta 115:688-93

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