Tuhin Khan

Institute of Macromolecular Chemistry | IMC · Department of Polymers for Electronics and Photonics

Nonlinear (vibrational) microscopy has emerged as a successful tool for the investigation of molecular systems as it combines label-free chemical characterization with spatial resolution on the sub-micron scale. In addition to the molecular recognition, the physics of the nonlinear interactions allows in principle to obtain structural information o...

The Cover Feature shows the carotenoid canthaxanthin (top) that is bound to orange carotenoid protein (OCP) and helical carotenoid protein (HCP) complexes depicted in the background of the orange (OCP) and purple (HCP) graphs. The transient absorption spectra obtained after visible‐light (green) or UV‐light (black) excitations demonstrate the diffe...

Over the last decade the orange carotenoid protein (OCP) gained attention due to its role in photoprotection in cyanobacteria. Recently, other carotenoid binding proteins such as helical carotenoid proteins (HCPs) have been identified and characterized, although the function of the HCPs is not yet clarified. Here we have examined OCP1 and two HCPs,...

Carotenoids are molecules with rich photophysics that are in many biological systems involved in photoprotection. Yet, their response to excess energy excitation is only scarcely studied. Here we have explored excited state properties of three keto‐carotenoids, echinenone, canthaxanthin and rhodoxanthin after excess energy excitation to a singlet s...

Recently a new family of carotenoproteins, homologs of the N-terminal domain of the orange carotenoid protein (NTD-OCP) have been identified in cyanobacteria. These homologs are called helical carotenoid proteins (HCPs) as they are all predicted to maintain the all-helical structure of the NTD-OCP and to bind carotenoid. Here, HCP2 and HCP3 isolate...

The keto-carotenoid deinoxanthin, which occurs in UV-resistant bacterium Deinococcus radiodurans, has been investigated by ultrafast time-resolved spectroscopic techniques. We have explored excited-state properties of deinoxanthin in solution and bound to the S-layer Deinoxanthin Binding Complex (SDBC), a protein complex important for UV resistance...

Fluorogenic molecules have attracted a significant share of both academic and industrial interests because of its wide range of real-time applications ranging from organic electronics to biochemical fields. The successful application of the fluorogenic molecules necessitates an in-depth understanding and manoeuvring of the photoinduced processes. I...

In this study, we have demonstrated an inversion in the efficiency of TiO2 and ZnO based dye sensitized solar cells for an organic sensitizer C343 and another Ru based sensitizer N719. Despite of faster electron injection from sensitizer C343 to TiO2 than ZnO, the later shows a better photovoltaic efficiency. The higher photocurrent in C343-ZnO has...

Fluorescence experiments at high fluorophore concentrations or in solid state have biological relevance and application potential in devices. Inner filter effect, arising from reabsorption of emitted photons, is the simplest of several factors that complicate the emission in these systems. This effect is prominent, especially for systems with small...

Salophen (N,N′-bis- (salicylidene)-o-phenylenediamine) is a Schiff base, which is weakly emissive in solutions, but strongly emissive in solid state. The trend is reversed in its aluminium complex (SalAl+), which is strongly emissive in solution, but feebly emissive in solid state. Thus, SalAl+ is not attractive for application as a solid state emi...

1-(2-Hydroxybenzyl)-2-(2-hydroxyphenyl)-1 H -benzimidazol-3-ium chloride, C 20 H 17 N 2 O 2⁺ ·Cl ⁻ , was prepared by reaction of salicylaldehyde with o -phenylenediamine in the presence of trimethylsilyl chloride acting as a source of HCl. As a result of steric hindrance, the cation in the crystal is far from planar: the benzimidazole ring system m...

Water plays a critical role in governing the intricate balance between chain-chain and chain-solvent interactions during protein folding, misfolding and aggregation. Previous studies have indicated the presence of different types of water in folded (globular) proteins. In this work, using femtosecond and picosecond time-resolved fluorescence measur...

Amyloids are cross-β-sheet fibrillar aggregates, associated with various human diseases and native functions such as protein/peptide hormone storage inside secretory granules of neuroendocrine cells. In the current study, using amyloid detecting agents, we show that growth hormone (GH) could be stored as amyloid in the pituitary of rat. Moreover, t...