Publications by authors named "Angshuman Das"

Temporal control over self-assembly processes is a highly desirable attribute that is efficiently exhibited by biological systems, such as actin filaments. In nature, various proteins undergo enzymatically catalysed chemical reactions that kinetically govern their structural and functional properties. Consequently, any stimuli that can alter their reaction kinetics can lead to a change in their growth or decay profiles.

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The amplification of asymmetry in supramolecular polymers has recently garnered significant attention. While asymmetry amplification has predominantly been explored under thermodynamic conditions, the kinetic aspect of this process unveils intriguing observations, yet is scarcely reported in the literature. Herein, drawing inspiration from macromolecular systems, we propose a novel strategy for enhancing asymmetry in supramolecular polymers through a seed-induced supramolecular polymerization approach under kinetic conditions, employing a naphthalene diimide-derived monomer (ANSG) for template-induced supramolecular polymerization, utilizing adenosine triphosphate (ATP) and pyrophosphate (PPi) as templates.

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Nature employs sophisticated mechanisms to precisely regulate self-assembly and functions within biological systems, exemplified by the formation of cytoskeletal filaments. Various enzymatic reactions and auxiliary proteins couple with the self-assembly process, meticulously regulating the length and functions of resulting macromolecular structures. In this context, we present a bioinspired, reaction-coupled approach for the controlled supramolecular polymerization in synthetic systems.

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Efficient circularly polarized luminescence (CPL) from purely organic molecules holds great promise for applications in displays, sensing, and bioimaging. However, achieving high dissymmetry values (g ) from organic chromophores remains a significant challenge. Herein, we present a bioinspired approach using adenosine triphosphate (ATP)-triggered supramolecular polymerization of a naphthalene diimide-derived monomer (ANSG) to induce CPL with a remarkable g value of 1.

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Synthesis of supramolecular block co-polymers (BCP) with small monomers and predictive sequence requires elegant molecular design and synthetic strategies. Herein we report the unparalleled synthesis of tri-component supramolecular BCPs with tunable microstructure by a kinetically controlled sequential seeded supramolecular polymerization of fluorescent π-conjugated monomers. Core-substituted naphthalene diimide (cNDI) derivatives with different core substitutions and appended with β-sheet forming peptide side chains provide perfect monomer design with spectral complementarity, pathway complexity and minimal structural mismatch to synthesize and characterize the multi-component BCPs.

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Synthesis of supramolecular block copolymers (BCPs) from small monomers has been recently attempted. However, the lack of dispersity and length control of the blocky segments limits its functional outcome. Herein we demonstrate the synthesis of well-defined supramolecular BCPs with tunable block lengths by varying the monomer to seed ratio in a kinetically controlled seeded supramolecular polymerization process.

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Wildlife trade and fraudulence in food, artefacts and cosmetic industries had raised serious concern in protection of the wild faunal diversity. Lack of proper tools and molecular based techniques for identification of wild species are some of the major constrains faced by the judiciary and law enforcement agencies while framing charges against poachers and illicit agitator. The emergence of wildlife forensics serves as a boon in solving long pending cases of wildlife crimes.

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Childhood visual impairment due to refractive errors is a significant problem in school children and has a considerable impact on public health. To assess the magnitude of the problem the present study was undertaken among the school children aged 5 to 10 years in Kolkata. Detailed ophthalmological examination was carried out in the schools as well as in the Regional Institute of Ophthalmology, Kolkata.

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Rhinosporidium seeberi, the causative organism causing rhinosporidiosis, also affects extranasal sites. A 1 5-year-old male presented with a conjunctival fleshy swelling near the inner canthus of the left eye. His visual acuity was within normal range.

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