Areas of Interest/Specialization:

• Time-resolved Fluorescence;
• Inclusion Complexes, Solvation Dynamics, Bio-molecular Interaction;
• Development of Fluorescence based Enzymatic Assay Method.

In general, several aspects on the above-mentioned problems are monitored with steady state and time resolved fluorescence spectroscopy. Ultrafast photo-processes and solvent response towards the formation of the transient species are probed with transient absorption and fluorescence up-conversion techniques in collaboration with several research groups in India & abroad. The experimental results are often supported with ab-initio/DFT calculations, molecular docking and molecular dynamics (MD) simulation.

Academic Experience:

• JSPS Postdoctoral Fellow: Kwansei Gakuin University, Japan (1997 - 1999)
• Postdoctoral Researcher: Katholieke University of Leuven, Belgium (1999 - 2000)
• Visiting Fellow: Department of Chemical Science, TIFR, Mumbai (2000 - 2001)
• Lecturer: Department of Chemistry, BITS, Pilani (2001 - 2003)
• JSPS Invitation Fellowship: Kwansei Gakuin University, Japan (2003), 3 months.
• Assistant Professor: Department of Chemistry, NEHU, Shillong (2003 - 2012)
• Visiting Professor C: Kwansei Gakuin University, Japan (2006), 2 months
• Associate Professor: Department of Chemistry, NEHU, Shillong (2012 - 2015)
• Professor: Department of Chemistry, NEHU, Shillong (2015 - onwards)

Academic affiliations 

Member of American Chemical Society (ACS), Indian Society for Radiation & Photochemical Sciences (ISRAPS), Fluorescence Society of India, Indian Photobiology Society etc.

Administrative Experience

• Member, University Court, NEHU, Shillong
• Member, Academic Council, NEHU, Shillong
• Member, School Board of Physical Sciences, NEHU, Shillong
• Member, Board of Studies in Chemistry, NEHU, Shillong
• Member, Departmental Research Committee, Department of Chemistry, NEHU, Shillong
• Member, Board of Studies in Physics, NEHU, Shillong
• Member, Board of Post-Graduate Studies in Mathematics, NEHU, Shillong
• Member, Board of Studies in Chemistry, Sikkim University

Research Projects

Research Projects Ongoing (02)

1. Study on anti-Alzheimer activity of coumarin based hybrid drugs: Synthesis and acetylcholinesterase inhibition assay (ICMR), Govt. of India (2022)
2. Photophysical Studies on polypyridyl complexes: Towards the development of nanoscopic fluorescent targets (DST-SERB), Govt. of India (2019 - 2022).

Research Projects Completed (07)

1. Excited state properties and relaxation dynamics of intramolecularly hydrogen bonded azo derivatives" Dept. of Science & Technology (DST), Govt. of India (2005 - 2008).
2. Spectroscopic characterization of intramolecular charge transfer type polarity sensors and their use in the study of protein - surfactant interaction" Council of Scientific & Industrial Research (CSIR), Govt. of India (2005 - 2008).
3. Construction and Multi-site Commissioning of Multiple Fluorescence Correlation Spectrometers (a single molecule biophotonic tool)" [as co-investigator, with Prof. S. Maiti of TIFR, Mumbai as chief-investigator], Dept. of Information & Technology (DIT), Govt. of India (2008 - 2011).
4. Spectroscopy and Dynamics of Photoinduced Processes in Homogeneous and Biomimetic Environments” University grants Commission (UGC), Govt. of India (2008 – 2011).
5. “Fluorescence Studies on Representative Intramolecular Photoprocesses in Homogeneous and Constrained Environments” Board of Research in Nuclear Sciences (BRNS), DAE, Govt. of India (2009 – 2012).
6. “Development of Ache-inhibitor for Alzheimer’s Disease: Screening, Designing, Synthesis and Biological validation using Chemical Library and North East Indian Plants” [as co-investigator, with Prof. K. Aguan of Biotechnology Dept., NEHU as principal investigator], Department of Biotechnology (DBT), Govt. of India (2011-2014).
7. “Spectrofluorimetric Investigation on Model Nitrogen Containing Heterocyclic Drugs and their Interaction with DNA Nucleotides” CSIR, Govt. of India (2012 – 2015).

Group members 

• Research Associate:
  Dr. Dhiman Ray (DSK Post-Doctoral Fellow); E-mail: dhimanray1@gmail.com  
• Ph.D ongoing: (4)
  i) Ms. Anindita Bhatta (aninditabhatta01@gmail.com); 
  ii). Mr. Deepak Chamlagai (dipakchamlagai1@gmail.com); 
  iii). Mr. Pynskhemborlang Tep Phanrang (pynskhemphanrang@gmail.com); 
  iv). Ms. Jahnabi Upadhyaya (jahnabiu@gmail.com)
• Ph.D completed:  (9)
  1. Dr. T. Sanjoy Singh (takhelsingh@gmail.com): Spectroscopic investigation on photo-induced intramolecular charge transfer process of donor-acceptor systems in homogeneous and micro-heterogeneous environments (2010).
  2. (ii) Dr. N. S. Moyon (bebemoyon@gmail.com): Solvatochromism and photophysical properties of alloxazine derivatives in homogeneous solvents and supramolecular assemblies (2011). 
  3. (iii) Dr. (Mrs.) S. Phukan (smrita4m@gmail.com): Fluorescence Studies on Biologically Relevant Heterocyclic Systems in Homogeneous Medium and Supramolecular Assemblies (2014). 
  4. (iv) Dr. P. Gashnga (miki.gash@gmail.com): Combined Experimental and Theoretical Studies on Photoinduced Hydrogen Transfer Processes (2016).
  5. (v) Dr. M. M Islam (islammuhai85@gmail.com): Fluorescence Based Studies on Drug-Receptor Interaction: Characterization of Acetylcholinesterase Inhibitors (2017). 
  6. (vi) Dr. V. K. Sonu (vikash9931@gmail.com): Fluorescence Based Investigation on the Effect of Nanoparticle on some Bi-molecular Conjugation Processes (2018).
  7. (vii) Dr. M A Rohman (rohmanmostofa@gmail.com): Fluorescence studies on            some organic molecules and their complexes with supramolecular hosts (2020).
  8. (viii) Dr. (Ms) P. Baruah (praya412@gmail.com): Spectroscopic Studies on the Modulatory Effect of Nano-bio interfaces on Some Selected Neurodegenerative and Mitochondrial Enzyme Activities (2022). 
  9. (ix) Dr. Rajkumar Imocha Singh (imocharajkumar@gmail.com): Development of functionalized nanoparticles and their applications in exploring bio-molecular milieu (2022)

Publications

Total number of publications: 115

1. “Modulated Antimicrobial Activity and Drug-Protein Interaction Ability of Zinc Oxide and Cadmium Sulfide Nanoparticles: Effect of Doping with Few First-Row Transition Metals” Imocha Rajkumar Singh, Upashna Chettri, Piyali Maiti, Anup K. Ghosh, S. R. Joshi and Sivaprasad Mitra, J. Cluster Sci. 2022. https://doi.org/10.1007/s10876-022-02257-y
2. "Auxiliary Therapeutic Role of Cholinergic Agents: Mechanistic Insights into the Antioxidant Behavior of AD Drugs towards Reversing DNA Oxidative Stress" Pynskhemborlang  Tep Phanrang, Prayasee Baruah, Asit K. Chandra, and Sivaprasad Mitra, J. Phys. Chem. A, 2022. https://doi.org/10.1021/acs.jpca.1c09146
3. "Elevated Fibrinogen Level Reduces Therapeutic Efficiency of AD Drugs: Biophysical Insights on the Interaction of FDA Approved Cholinesterase Inhibitors with Human Fibrinogen" Prayasee Baruah, Debojit Paul, Jitesh Doshi, and Sivaprasad Mitra, J. Phys. Chem. B, 2022, 126, 30 – 43. https://doi.org/10.1021/acs.jpcb.1c07495
4. "Deciphering Spectroscopic and Structural Insights into the Photophysical Behavior of 2, 2'-Dipyridylamine: An Efficient Environment Sensitive Fluorescence Probe" Mostofa Ataur Rohman, Pynskhemborlang Tep Phanrang, Dipak Chamlagai and Sivaprasad Mitra, J. Phys. Chem. A, 2021, 125, 6964-6975. https://doi.org/10.1021/acs.jpca.1c04772
5. “Cholinergic drugs bind at minor groove and reverse induced oxidative stress of calf thymus DNA: A new perspective towards an unexplored therapeutic efficacy” Prayasee Baruah, Pynskhemborlang Tep Phanrang, Ibemhanbi Konthoujam, Kripamoy Aguan, and Sivaprasad Mitra, New Journal of Chem., 2021, 45, 13925 – 13933. https://doi.org/10.1039/D1NJ01911B
6. “Dietary polyphenols inhibit plasma protein arabinosylation: Biomolecular interaction of genistein and ellagic acid with serum albumins” Imocha Rajkumar Singh, Semen O. Yesylevskyy, and Sivaprasad Mitra, Biophys. Chem., 2021. https://doi.org/10.1016/j.bpc.2021.106651
7. “Sulfonylurea class of anti-diabetic drugs inhibit acetylcholinesterase activity: Unexplored auxiliary pharmacological benefit towards Alzheimer’s Disease” Prayasee Baruah, Abhinandan Das, Debojit Paul, Suman Chakrabarty, Kripamoy Aguan, and Sivaprasad Mitra, ACS Pharmacology & Translational Science, 2021, 4, 193 – 205. https://doi.org/10.1021/acsptsci.0c00168
8. “Modulation of enzyme activity at nano-bio interface: A case study with acetylcholinesterase and citrate synthase adsorbed on colloidal metal nanoparticles” Prayasee Baruah, Semen O. Yesylevskyy, Kripamoy Aguan, and Sivaprasad Mitra, J. Mol. Liq., 2021, xx, xx – xx. https://doi.org/10.1016/j.molliq.2020.115201
9. "Fluorescence solvatochromism and modulated anticholinergic activity of novel coumarin compounds sequestered in human serum albumin nanocavities" Mostofa Ataur Rohman, Prayasee Baruah, Deboshikha Bhattacharjee, B. Myrboh, and Sivaprasad Mitra, New Journal of Chem., 2019, 43, 18713-18725. DOI: 10.1039/C9NJ03293B
10. “Excited state decay dynamics in 3-formyl-4-hydroxy benzoic acid: Understanding the global picture of an ESIPT driven multiple emissive species” Mostofa Ataur Rohman, Dipankar Sutradhar, Prakriti Ranjan Bangal, Asit K Chandra, and Sivaprasad Mitra, ChemistrySelect, 2019, 4, 6702 - 6712.
11. "Fluorescence solvatochromism and modulated anticholinergic activity of novel coumarin compounds sequestered in human serum albumin nanocavities" Mostofa Ataur Rohman, Prayasee Baruah, Deboshikha Bhattacharjee, B. Myrboh, and Sivaprasad Mitra, New Journal of Chem., 2019, DOI: 10.1039/C9NJ03293B.
12. “Specific solvent effect on the photophysical behavior of substituted chromones: A combined fluorescence, DFT and MD study” Mostofa Ataur Rohman, Prayasee Baruah, Semen O. Yesylevskyy, and Sivaprasad Mitra, Chemical Physics, 2019, 517, 67 – 79. DOI: 10.1016/j.chemphys.2018.09.042
13. “Novel Coumarin Derivatives as Potent Acetylcholinesterase Inhibitors: Insight into Efficacy, Mode and Site of Inhibition”, Prayasee Baruah, Grace Basumatary, Semen O. Yesylevskyy, Kripamoy Aguan, Ghanashyam Bez, and Sivaprasad Mitra, J. Biomolecular Structure and Dynamics, 2018. DOI: 10.1080/07391102.2018.1465853.
14. “Interaction of caffeine and sulfadiazine with Lysozyme adsorbed at colloidal metal nanoparticle interface: Influence on drug transport ability and antibacterial activity”, Vikash K. Sonu, Imocha Rajkumar, Kaushik Bhattacharjee, S. R. Joshi, and Sivaprasad Mitra, J. Biomolecular Structure and Dynamics, 2018. DOI: 10.1080/07391102.2018.1426497.
15. “Serum albumin interaction with xanthine drugs at nano-bio interfaces: A combined multi-spectroscopic and molecular modelling approach”, Vikash K. Sonu, Mullah Muhaiminul Islam, Arun Bahadur Gurung, Atanu Bhattacharjee, and Sivaprasad Mitra, J. Mol. Liq., 2017, 242, 919 - 927.
16. “Photophysical behavior of systematically substituted (di-2-pyridylaminomethyl) benzene ligands and its Re(l) complexes: A combined experimental and theoretical approach”, M. A. Rohman, D. Sutradhar, S. Sangilipandi, K. Mohan Rao, Asit K. Chandra, Sivaprasad Mitra, J. Photochem. Photobiol. A: Chemistry, 2017, 341, 115 – 126.
17. “Cholinergic inhibitors replace thioflavin-T from acetylcholinesterase binding pocket: A potential fluorescence based molecular switch”, Mullah Muhaiminul Islam, and Sivaprasad Mitra, Chem. Phys. Letts. 2016, 664, 63 – 69.
18. “Lysozyme binding ability toward psychoactive stimulant drugs: Modulatory effect of colloidal metal nanoparticles” Vikash K. Sonu, Mullah Muhaiminul Islam, Mostofa Ataur Rohman, and Sivaprasad Mitra, Colloids and Surfaces B: Biointerfaces, 2016, 146, 514 – 522.
19. “Fluorescence properties and sequestration of peripheral anionic site specific ligands in bile acid hosts: Effect on acetylcholinesterase inhibition activity” Mullah Muhaiminul Islam, Kripamoy Aguan, and Sivaprasad Mitra, J. Photochem. Photobiol. B. Biology, 2016, 158, 192 – 201.
20. “Human serum albumin reduces the potency of acetylcholinesterase inhibitor based drugs for Alzheimer's disease” Mullah Muhaiminul Islam, Arun Bahadur Gurung, Atanu Bhatacharjee, Kripamoy Aguan, and Sivaprasad Mitra, Chemico-Biological Interactions 2016, 249, 1 – 9.
21. “Intramolecular charge transfer in coumarin based donor-acceptor systems: Formation of a new product through planar intermediate” S. Phukan, M. Saha, A. K. Pal, A.C. Bhasikuttan, and S. Mitra, J. Photochem. Photobiol. A: Chemistry, 2015, 303, 67 – 79.
22. “Specific Solvent Effect on Lumazine Photophysics: A Combined Fluorescence and Intrinsic Reaction Coordinate Analysis”, N. S. Moyon, P. M. Gashnga, S. Phukan, S. Mitra, Chem. Phys., 2013, 421, 22 - 31.
23. “Fluorescence Modulation and Associative Behavior of Lumazine in Hydrophobic Domain of Micelles and Bovine Serum Albumin” N. S. Moyon, M. M. Islam, S. Phukan, S. Mitra, J. Photochem. Photobiol. B: Biology, 2013, 121, 37 - 45.
24. “Luminol Fluorescence Quenching in Bio-mimicking Environments: Sequestration of Fluorophore in Hydrophobic Domain” N. S. Moyon and Sivaprasad Mitra, J. Phys. Chem. B. 2011, 115, 10163 - 10172.
25. "Fluorescence Solvatochromism in Lumichrome and Excited State Tautomerization: A Combined Experimental and DFT Study" N. S. Moyon and Sivaprasad Mitra, J. Phys. Chem. A. 2011, 115, 2456 - 2464.

Invited Talks in Conferences/Seminars

Organization of Conferences/Symposia:

• Convener of “National Workshop on Fluorescence Correlation Spectroscopy & Biophotonics (FCS-2010)” held at North-Eastern Hill University, Shillong, Nov 8 -13, 2010.
• Vice-Chairman of the local organising committee for the BRNS-AEACI Ninth School on Analytical Chemistry (SAC-9) held at Atomic Minerals Directorate, NE Region, Shillong during Oct 27 – Nov 03, 2014.    
• Convener of National Seminar on contemporary Challenges in Chemistry (NSC3-2018) held at North-Eastern Hill University, Shillong, Nov 20-21, 2018.