The central approach of this laboratory is the mechanistic investigation of photo-induced processes of important organic and inorganic molecules in real time. Primarily we are devoted to investigate the excited state characteristics of broad range of molecules in the time scale ranging from femtoseconds to nanoseconds. The brief fields of interest include the dynamics of biological macromole-cules like proteins, DNA, etc., the excited state ultrafast dynamics of many novel chromophores like fluorescent protein chromophore analogs, metal complexes, etc. Effect of nano-confinement and heterogenous media also share one of the prime locus of research in the laboratory. The main aim is to interpret natural observation and to gain complete knowledge of system property from the knowledge of excited state relaxation dynamics. In addition we are as well commencing the non-linear laser spectroscopic study of liquid-air and solid-air interfaces.
Our laboratory is equipped with

1. Femtosecond transient absorption spectrometer
2. Femtosecond fluorescence up-conversion spectrometer
3. Picosecond TCSPC system
4. Steady state fluorimeter
5. Spectrophotometer
6. Home built fluorescence correlation spectrometer etc.

Our group have studied the ultrafast excited state relaxation dynamics of important NLO dye to trace the relaxation pathways and connected to its properties. This work became one of the most read articles in The Journal of Physical Chemistry A. We also have confirmed the role of protein scaffold in reducing the non-radiative pathways, leading to highly luminescent nature of wild type GFP by studying GFP chromophore analogs. Using ultrafast laser spectroscopy, we also have measured the microviscosity of water trapped in AOT reverse-micelle to explore the possibility of using ultrafast dynamics to understand the system property.

• Mechanistic investigation of domain specific unfolding of human serum albumin and the effect of sucrose,
  Protein Sci., 22, 1571 (2013).

• Spectroscopic evidence of the presence of an activation barrier in the otherwise barrierless excited state potential energy surface of
  auramine-O: A femtosecond fluorescence up-conversion study,
  J. Chem. Phys., 139, 124302 (2013).

• Dielectric Controlled Excited State Relaxation Pathways of a Representative Push-Pull Stilbene: A Mechanistic Study using Femtosecond Fluorescence Up-
  conversion Technique,
  J. Chem. Phys., 138, 084308 (2013).

• Quantitative estimate of the water surface pH using heterodyne-detected electronic sum frequency generation,
  J. Chem. Phys., 137, 151101 (2012).

• Origin of Strong Synergism in Weakly Perturbed Binary Solvent System: A Case Study of Primary Alcohols and Chlorinated Methanes,
  J. Phys. Chem. B, 116, 1345 (2012).

• Femtosecond Excited State Dynamics of 4-Nitrophenyl Pyrrolidinemethanol: Evidence of Twisted Intramolecular Charge Transfer and Intersystem Crossing involving Nitro Group,
  J. Phys. Chem. A, 115, 8335 (2011).

• JSPS Fellow, 2006-2008.

• Indian Institute of Technology Kanpur, 2008-

• Post Doc., RIKEN, Japan, 2006-2008

• P. K. Kelkar Research Fellowship, Young Faculty Research fellowships, IITK, 2015

• Young Scientist Medal, Indian National Science Academy, New Delhi, 2013

Office

Core Lab 101B,
Department of Chemistry
IIT Kanpur,
Kanpur 208016

Office Phone: 0512-259-6312 (O)

Email: psen[AT]iitk.ac.in