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Krishanu  Ray

Krishanu Ray Ph.D.

Academic Title: Associate Professor
Primary Appointment: Biochemistry and Molecular Biology
Location: 725 W. Lombard St., N255
Phone: (410) 706-7500
Fax: (410) 706-8408

Personal History:

Dr. Ray is an Associate Professor at the Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore. He received his M.S. degree in physics from Indian Institute of Technology Kharagpur and Ph.D. degree in spectroscopy from the Indian Association for the Cultivation of Science, India. Prior to joining at the University of Maryland, he was a Postdoctoral Associate at the Yale University focusing his research in the area of single molecule imaging spectroscopy. He was a visiting scientist at the Weizmann Institute of Science where he worked on electron transmission through organized organic thin films. Currently Dr Ray is a member of the editorial boards for the Journal of Bioanalysis and Biomedicine and ISRN Nanotechnology. He served as co-conference chair for the Plasmonics in Biology and Medicine of the SPIE Photonics West. He is a permanent member of the program committee of the SPIE meeting. Dr. Ray received NIH Career Award for his research on single molecule studies of HIV envelope properties. He reviews manuscripts for many international journals including several ACS and RSC journals on a regular basis. He review grants for different national and international agencies. Dr Ray serves as an ad hoc reviewer for the National Institutes of Health study panels.

Research Interests:

Single molecule imaging spectroscopy, Fluorescence correlation spectroscopy, Metal enhance fluorescence, Surface plasmon coupled emission, Plasmon-controlled fluorescence, Radiative decay engineering, Fluorescence spectroscopy, Chemically amplified photoresists, Langmuir-Blodgett films, Layer-by-layer assembly, Nanotechnology, Plasmonic Nanostructures, Application of single molecule spectroscopy in biomedical research, Viral nucleic acid packaging, Single molecule studies of HIV proteins.

Dr. Ray has successfully obtained NIH funding, published about 70 peer-reviewed manuscripts in excellent and outstanding journals (H index = 18), filed three US patent applications, developed a successful program to provide spectroscopy expertise on campus, and developed new and novel technologies. Three research contributions are of particular importance:

  1. Plasmon-controlled fluorescence applications in biomedical science

    The goal of the research in this area is focused on understanding the correlation between plasmonic nanostructures, excitation light and enhanced fluorescence. He has developed new techniques and methodology to apply this technology in biology.

  2. Single molecule studies of the HIV envelope.

    Research in this area is focused on the biophysical properties of HIV proteins. Fluorescence correlation spectroscopy (FCS) and single molecule detection (SMD) are used as novel tools to probe the nature of HIV-1 envelope interactions with cell surface receptors and/or anti-envelope antibodies at the molecular level to understand the initial step of HIV infection.

  3. DNA packaging motor dynamics

    The primary objective is to directly probe the mechanism of the viral DNA packaging motor using single molecule fluorescence-based approaches. Fluorescence measurements have the most potential to establish motor dynamics and structural changes to the DNA substrate that accompany translocation.

Dr. Ray also has a second major role as Associate Director of the Center for Fluorescence Spectroscopy. In this role he manages the high-end instrumentation obtained from NIH instrument grant applications, trains and mentors investigators and their staff in the application of this technology, teaches individuals how to use the instrumentation, and provides intellectual leadership regarding application of these technologies to biological problems. This is a highly collaborative effort where he assists a large number of faculty members in utilizing this technology.

Honors & Awards:

  • NIH Career Grant Award, 2011
  • Japan Society for the Promotion of Science (JSPS) Fellowship, 2000
  • “ISCA Young Scientists’ Award 1997-98” in Physics from Indian Science Congress Association


Selected Publications

K. Ray, S.P. Ananthavel, D.H. Waldeck, R. Naaman, Asymmetric scattering of polarized electrons by organized organic films of chiral molecules, Science, 1999, 283, 814-816.

Krishanu Ray, H. Nakahara, Adsorption of sulforhodamine in cationic Langmuir-Blodgett films: Spectroscopic and structural studies, J. Phys. Chem. B 2002, 106, 92-100.

M.D. Mason, Krishanu Ray, R.D. Grober, G. Pohlers, J. Cameron, Single molecule acid/base kinetics and thermodynamics, Physical Review Letters, 2004, 93, 073004. Selected for the August 15, 2004 issue of Virtual Journal of Biological Physics Research, covering a focused area of frontier research.

Krishanu Ray*, M.D. Mason, G. Pohlers, J. Cameron, R.D. Grober, Quantum yields of photoacid generation in 193nm chemically amplified resists by fluorescence imaging spectroscopy, Chem. Mater.2004, 16, 5726 - 5730.

Krishanu Ray, M.D. Mason, C. Yang, Z. Li, R.D. Grober, Single molecule signal enhancement using a high-impedance ground plane, Appl. Phys. Lett, 2004, 85, 5520.

Krishanu Ray, R. Badugu, J. R. Lakowicz, Metal-enhanced fluorescence from CdTe nanocrystals: A single-molecule fluorescence study, J. Am. Chem. Soc.  2006, 128, 8998-8999.

Krishanu Ray, R. Badugu R, J.R. Lakowicz, Polyelectrolyte layer-by-layer assembly to control the distance between fluorophores and plasmonic nanostructures. Chem. Mater. 2007, 19, 5902-9.

Krishanu Ray, H. Szmacinski, J. Enderlein, J.R. Lakowicz, Distance-dependence of surface plasmon-coupled emission observed using Langmuir-Blodgett films, Appl. Phys. Lett. 2007, 90, 251116.

Krishanu Ray, M.H. Chowdhury MH, J.R. Lakowicz, Aluminum nanostructured films as substrates for enhanced fluorescence in the ultraviolet-blue spectral region, Anal. Chem. 2007, 79, 6480-7 (Accelerated Article).

Krishanu Ray*, M.H. Chowdhury, J.R. Lakowicz, Single molecule spectroscopic study of enhanced intrinsic phycoerythrin fluorescence on silver nanostructured surfaces, Anal. Chem. 2008, 80, 6942-6948. (Cover Article)

Krishanu Ray*, J. Zhang, J.R. Lakowicz, Fluorescence lifetime correlation spectroscopic study of fluorophore-labeled silver nanoparticles, Anal. Chem. 2008, 80, 7313 – 7318.

Krishanu Ray*, H. Szmacinski, J.R. Lakowicz, Enhanced fluorescence of proteins and label-free bioassays using aluminum nanostructures, Anal. Chem. 2009, 80, 7313 - 7318.

Krishanu Ray, M. Oram, J. Ma, L.W. Black, Portal control of viral prohead expansion and DNA packaging, Virology, 2009 391, 44-50.

Krishanu Ray, J. Ma, M. Oram, J. R. Lakowicz, L. W. Black, Single Molecule- and Fluorescence Correlation Spectroscopy-FRET Analysis of Phage DNA Packaging: Co-localization of the Packaged Phage T4 DNA Ends within the Capsid. J. Mol. Biol., 2010 395, 1102-1113.

Krishanu Ray, C. Sabanayagam, J.R. Lakowicz, L.W. Black, DNA crunching by a viral packaging motor: Compression of a procapsid-portal stalled Y-DNA substrate, Virology, 2010, 398, 224-32.

A. Dixit, Krishanu Ray, J. R. Lakowicz, L. W. Black, Dynamics of the T4 Bacteriophage DNA Packasome Motor: endonuclease VII resolvase release of arrested Y-DNA substrates. J. Biol. Chem., 2011, 286, 18878-18889.

M. L. Markwardt, G. Kremers,  C.A. Kraft, Krishanu Ray, P.J.C. Cranfill, K.A. Wilson, R.N. Day, R.M. Wachter, M.W. Davidson, M.A. Rizzo, An Improved Cerulean Fluorescent Protein with Enhanced Brightness and Reduced Reversible Photoswitching, PLOS One, 2011, 6, e17896 (1-11).

M.H. Chowdhury, J.R. Lakowicz, Krishanu Ray*, Ensemble and Single Molecule Studies on the Use of Metallic Nanostructures to Enhance the Intrinsic Emission of Enzyme Cofactors, J. Phys. Chem. C., 2011 115, 7298-7308.

M.H. Chowdhury, S. Chakraborty, J.R. Lakowicz, Krishanu Ray*, Feasibility of Using Bimetallic Plasmonic Nanostructures to Enhance the Intrinsic Emission of Biomolecules, J. Phys. Chem. C., 2011, 115, 16879–16891.

D.K. Ghosh, Krishanu Ray, A.J. Rogers, N.J. Nahm, J.C. Salerno, FMN Fluorescence in Inducible NOS Constructs Reveals a Series of Conformational States Involved in the Reductase Catalytic Cycle, FEBS J. 2012, 279, 1306-1317.

N. Akbay, J. R. Lakowicz, Krishanu Ray*, Distance-Dependent Metal-Enhanced Intrinsic Fluorescence of Proteins Using Polyelectrolyte Layer-by-Layer Assembly and Aluminum Nanoparticles, J. Phys. Chem. C, 2012, 116, 10766–10773.

S. DuttaChoudhury, Krishanu Ray, J.R. Lakowicz, Silver Nanostructures for Fluorescence Correlation Spectroscopy: Reduced Volumes and Increased Signal Intensities, J. Phys. Chem. Lett, 2012, 3, 2915–2919.

M. Chowdhury, N. Lindquist, A. Lesuffleur, S. Oh, J. R. Lakowicz, Krishanu Ray*, Effect of Nanohole Spacing on the Self-Imaging Phenomenon Created by the Three-Dimensional Propagation of Light through Periodic Nanohole Arrays, J. Phys. Chem. C, 2012, 116, 19958–19967.

A. Dixit, Krishanu Ray, L. Black, Compression of the DNA substrate by a viral packaging motor is supported by removal of intercalating dye during translocation, Proc Natl Acad Sci U S A. 2012,109, 20419-24.

Krishanu Ray*, J.R. Lakowicz Metal-enhanced fluorescence lifetime imaging and spectroscopy on a modified SERS substrate, J. Phys. Chem C, 2013, 117, 15790–15797.

Krishanu Ray*, M. Mengistu, J.R. Lakowicz, G. Lewis G., A.L. DeVico, Antigenic properties of HIV envelope on virions in solution, J. Virology, 2014, 88, 1795-1808.