Marco A. De Jesús Associate Professor Analytical & Environmental Chemistry Chemical separations; chemical sensing; Raman spectroscopy B.S., UPR, Mayagüez (1993) Ph.D., UT, Knoxville (2004) Post. Doc., UT, Knoxville (2005) WebPage: moodle.uprm.edu/

Office: Q-019 Chemistry Building, Mayagüez, PR 00681 Lab.: Q-031 Phone: (787) 832-4040    2911 e-mail:marco.dejesús@upr.edu

Research:

Analytical chemical separations: Our separations research program is dedicated to the development of liquid and gas chromatography procedures for trace detection of pharmaceutical and personal care products (PPCPs), pesticides antimicrobials and other emerging pollutants of environmental interest.  Fundamental work focuses on studies involving colloidal suspensions as additives in surface and wastewater treatment.  These additives include polymer microcomposites, encapsulated iron and titanium dioxide microspheres, and natural fibers. Our separations work is applied to samples of environmental, agricultural, and pharmaceutical significance.

Chemical Sensing: Methods to nanolithographically construct dense arrays of metal nanocomposites as plasmonic sensors are being developed. Procedures to depositing noble metals and transition/noble metals alloys on the immobilized nanostructures to investigate the interfacial interactions of neuritic deposits, food pathogens, antimicrobial drugs and bioactive agents of environmental and biomedical significance are being developed. The composite surface acts as a molecular recognition element with sorptive and optical properties that can be tailored for enhanced selectivity and operational wavelengths. The nanostructured surfaces are used to increase the effective Raman cross section and loading capacity enabling an enhanced surface plasmon excitation for the detection and quantitation of bioactive agents in a variety of matrices by Surface Enhanced Raman Scattering.  Applications for these novel sensing technologies abound in the environmental, biomedical, food safety and toxicological fields.

Raman Spectroscopy: Sensitive methods for the Raman detection of antimicrobials, b-amyloid peptides, and food pathogens via SERS detection are being developed using nanolithography and physical vapor deposition (PVD) methods. The sensitivity and detailed structural information attainable through SERS has been exploited for the detection of a variety of aromatic pollutants of environmental significance (arsenic drugs, fluoroquinolones, bacterial strains, etc.).

Representative publications

1.    Surface Enhanced Raman Characterization of Trace Organoarsenic Antimicrobials Using Silver/Polydimethylsiloxane; Olavarría-Fullerton J.; Wells, S.; Ortiz-Rivera, W.; Sepaniak, M. J.  De Jesús, M.A. Surface Enhanced Raman Characterization of Trace Organoarsenic Antimicrobials Using Silver/Polydimethylsiloxane Nanocomposites, Applied Spectroscopy, (2011) 65 (4) 423-428 .

2.     NanocompositesDe Jesús, M. A.; Giesfeldt, K. S.; Oran, J. M.; Abu-Hatab, N. A.; Lavrik, N. V.; Sepaniak, M. J.   Nanofabrication of densely packed metal-polymer arrays for surface-enhanced Raman spectrometry.    Applied Spectroscopy  (2005),  59(12),  1501-1508.

3.    Giesfeldt, Kathleen S.; Connatser, R. Maggie; De Jesús, M. A.; Dutta, Pampa; Sepaniak, Michael J..   Gold - polymer  nanocomposites: Studies of their optical properties and their potential as SERS substrates.    Journal of Raman Spectroscopy  (2005),  36(12), 1134-1142. 

4.      De Jesús M. A.; Giesfeldt, K. S.; Sepaniak, M. J.;  “Factors affecting the sorption of model environmental pollutants onto silver polydimethylsiloxane nanocomposite Raman substrates”.    Applied Spectroscopy  (2004),  58(10), 1157-1164 

5.      De Jesús, M. A.; Giesfeldt, K. S.; Sepaniak, M. J. (2004); “Improving the analytical figures of merit of SERS for the analysis of model environmental pollutants.”    Journal of Raman Spectroscopy  (2004),  35(10),  895-904

Biographical sketch

Dr. De Jesús received his B.S. in Chemistry from the University of PR at Mayagüez in 1993 and his Ph.D. in Analytical Chemistry from the University of Tennessee, Knoxville in 2004. He joined the faculty of the University of Puerto Rico in Mayagüez after completing his post doctorate in 2005. He is the Graduate program coordinator and an active member of the Analytical & Environmental Chemistry Divisions. Dr. Dejesus is professor and coordinator of the Analytical and Instrumental Analysis courses and laboratories.  His graduate level coursework include among others: Advanced Analytical Chemistry, Advanced Environmental Chemistry, Methods for Environmental Trace Analysis, Chemical Aspects of Environmental Problems, and Analytical Applications of Raman Spectroscopy.