The Spectroscopy Group
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Our Research:

Photophysical characterization of new organic and inorganic molecules in microheterogeneous environments

We synthesize new biologically compatible organic and inorganic fluorophores, characterize them and apply in host-guest chemistry. Knowledge on binding of compounds to bio-compatible carriers and their subsequent transit followed by release to the target sites need to be known essentially to develop drug delivery. 

Host-guest interaction and applications in biological environments

The bound guest molecules to corresponding hosts may change the morphology of the latter subsequently generating molecular suprastructures that create provisions for trapping ions. The dynamics of the process is understood using various spectroscopic techniques.

Synthesis and application of metal nanoparticles and nanoclusters in drug delivery

We synthesize noble metal nanoparticles and nanoclusters and apply them in drug delivery following biological compatibility. The metal nanoclusters show fluorescence signals as opposed to the nanoparticles that makes them usable as bio-markers. Guest-host chemistry can be applied to develop bio-remedies for various physiological malfunctions.

Carbon nanoparticles in photoinduced energy/electron transfer

Photoinduced electron transfer is a smart concept to learn as this encompasses various applications including energy harvesting devices. We use carbon based nanomaterials, including nanoparticles, nanotubes and nanoplatelets to look into interactions with various energy donating/accepting substances in view of understanding the underlying dynamics.

Fluorescence Lifetime Imaging (FLIM) and Fluorescence Correlation Spectroscopy (FCS)

These microscopy based techniques are used in our laboratory to justify the positioning of various guests in bio-compatible hosts, such as, lipid vesicles. Entrapment of the fluorescent species withing bilayers alters the inherent photophysics of the guests that are significant to understand before applications to drug delivery.

Selected Recent Publications:

  • A. Ghosh, S. K. Seth and P. Purkayastha, Surfactant and cyclodextrin induced vesicle to micelle to vesicle transition in aqueous medium, Langmuir 34, 201811503–11509.
  • R. Banerjee and P. Purkayastha, Interaction of coumarin 6 with carbon nanotubes: Disintegration of the microcrystalline state by surfactant aggregation on the nanotube surface, J. Mol. Liq. 271, 2018, 397-402.
  • D. Halder and P. Purkayastha, A flavonol that acts as a potential DNA minor groove binder as also an efficient G-quadruplex loop binder, J. Mol. Liq. 265, 2018, 69-76.
  • S. Bhunia, S. Kumar and P. Purkayastha, Gold nanocluster-grafted cyclodextrin suprastructures: formation of nanospheres to nanocubes with intriguing photophysics, ACS Omega 3, 2018, 1492-1497
  • R. Banerjee and P. Purkayastha, Piecemeal rekindling of Coumarin 6 fluorescence on stepwise unfolding of protein by surfactant, J. Phys. Chem. B 121, 2017, 11449−11454.
  • S. Das and P. Purkayastha, Modulating Thiazole Orange aggregation in giant lipid vesicles: Photophysical study associated with FLIM and FCS, ACS Omega 2, 2017, 5036-5043.
  • R. Banerjee and P. Purkayastha, Revival of nearly extinct fluorescence of coumarin 6 in water and complete transfer of energy to rhodamine 123, Soft Matter 13, 2017, 5506-5508.
  • S. Das and P. Purkayastha, A fluorescence lifetime imaging microscopy (FLIM) supported investigation on temperature dependent penetration of dopamine in DMPG lipid bilayer, Langmuir, 33, 2017, 7281-7287.
  • S. K. Seth, P. Gupta and P. Purkayastha, Efficiency of photoinduced electron transfer in mono- and di-nuclear iridium complexes: A comparative study, New J. Chem., 41, 2017, 6540-6545.