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Krishanu Ray, PhD

Academic Title:

Associate Professor

Primary Appointment:

Biochemistry and Molecular Biology

Additional Title:

Associate Professor, Vaccine Division, Institute of Human Virology


725 W. Lombard St., N655

Phone (Primary):

(410) 706-6175


(410) 706-4694

Education and Training

Dr. Ray 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.


Dr. Ray is an Associate Professor at the Department of Biochemistry and Molecular Biology and Institute of Human Virology, University of Maryland School of Medicine, Baltimore. Currently Dr Ray is a member of the editorial boards for the Journal of Bioanalysis and Biomedicine and ISRN Nanotechnology. He is a 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 and NIH R01 grant for his research on conformational dynamics of HIV envelope by single molecule fluorescence. He reviews manuscripts for many international journals including several ACS and RSC journals on a regular basis. He reviews grants for different national and international agencies. Dr Ray serves as an ad hoc reviewer for the National Institutes of Health study panels.

Research/Clinical Keywords

Single Molecule Fluorescence Spectroscopy, Super-resolution imaging, HIV Envelope, Fc gamma receptor, DNA Packaging Motor, Plasmonics

Highlighted Publications

 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. Lakowicz, G. Lewis, A. DeVico. Antigenic properties of HIV envelope on virions in solution, J. Virology, 2014, 88, 1795-1808.

M. Mengistu, Krishanu Ray, G. Lewis, A. DeVico (2015). Antigenic properties of the human immunodeficiency virus envelope glycoprotein gp120 on virions bound to target cells, PLOS Pathogen, 11, e1004772.

Krishanu Ray*, R. Badugu, H. Szmacinski, J. Lakowicz, Several hundred-fold enhanced fluorescence from single fluorophores assembled on silver nanoparticle–dielectric–metal substrate, Chemical Communications, 2015, 51, 15023-15026.

E. Barnoy, D. Fixler, R. Popovtzer, T. Nayhoz, Krishanu Ray* An ultra-sensitive dual-mode imaging system using metal-enhanced fluorescence in solid phantoms., Nano Res. 2015, 8, 3912-3921.

Additional Publication Citations

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.

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, 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, 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, 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, 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.

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.

D. Fixler, T. Nayhoz, Krishanu Ray*, Diffusion reflection and fluorescence lifetime imaging microscopy study of fluorophore-conjugated gold nanoparticles or nanorods in solid phantoms, ACS Photonics, 2014, 1, 900–905.

N. Gohain, W. Tolbert, P. Acharya, L. Yu, T. Liu, P. Zhao, C. Orlandi, M. Visciano, R. Kamin-Lewis, M. Sajadi, L. Martin, J. Robinson, P. Kwong, A. DeVico, Krishanu Ray, G. Lewis, M. Pazgier, Co-crystal structures of antibody N60-i3 and antibody JR4 in complex with gp120 define more Cluster A epitopes involved in effective antibody-dependent effector function against HIV-1, J. Virology, 2015, 89, 8840-54.

N. Gohain, WD Tolbert, C. Orlandi, J. Richard, S. Ding, X. Chen, D. Bonsor, E. Sundberg, W. Lu, Krishanu Ray, A. Finzi, G. Lewis, M. Pazgier, Molecular basis for epitope recognition by non-neutralizing anti-gp41 antibody F240. Scientific Reports 2016, 6, 36685. 

W. Tolbert, N. Gohain, N. Alsahafi, V. Van, C. Orlandi, S. Ding, L. Martin, A. Finzi, G. Lewis, Krishanu Ray, M. Pazgier Targeting the Late Stage of HIV-1 Entry for Antibody-dependent Cellular Cytotoxicity: Structural Basis for Env Epitopes in the C11 Region, Structure, 2017, in press.

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 over 80 peer-reviewed manuscripts in excellent and outstanding journals (H index = 23), 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) Single molecule studies of the HIV envelope and Fc gamma receptors   

 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.

2) 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.

 3) 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.

Awards and Affiliations

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.

Grants and Contracts

NIH/NIGMS R01GM117836 Conformational Dynamics of HIV Envelope by Single Molecule Spectroscopy

NIH/NIGMS R01GM117836-S1 Conformational Dynamics of HIV Envelope by Single Molecule Spectroscopy

NIH/NIAID K25 AI087968 Single Molecule Studies of HIV Envelope Properties

Lab Techniques and Equipment

Single Molecule Imaging, Fluorescence Correlation Spectroscopy, FRET, Time-resolved Fluorescence, Confocal Microscopy, TIRF, Fluorescence Lifetime Imaging Microscopy, Super-resolution Microscopy