@article {47158,
	title = {Nanoparticle size-fractionation through self-standing porous covalent organic framework films},
	journal = {Angewandte Chemie-International Edition},
	volume = {59},
	year = {2020},
	month = {JAN},
	pages = {1161-1165},
	type = {Article},
	abstract = {<p>Covalent organic frameworks (COFs) have attracted attention due to their ordered pores leading to important industrial applications like storage and separation. Combined with their modular synthesis and pore engineering, COFs could become ideal candidates for nanoseparations. However, the fabrication of these microcrystalline powders as continuous, crack-free, robust films remains a challenge. Herein, we report a simple, slow annealing strategy to construct centimeter-scale COF films (Tp-Azo and Tp-TTA) with micrometer thickness. The as-synthesized films are porous (SA(BET)=2033 m(2) g(-1) for Tp-Azo) and chemically stable. These COFs have distinct size cut-offs (ca. 2.7 and ca. 1.6 nm for Tp-Azo and Tp-TTA, respectively), which allow the size-selective separation of gold nanoparticles. Unlike, other conventional membranes, the durable structure of the COF films allow for excellent recyclability (up to 4 consecutive cycles) and easy recovery of the gold nanoparticles from the solution.</p>
},
	keywords = {covalent organic frameworks, films, nanofilter, Nanoparticles, size-selective separation},
	issn = {1433-7851},
	doi = {10.1002/anie.201912381, Early Access Date = DEC 2019},
	author = {Dey, Kaushik and Kunjattu, Shebeeb H. and Chahande, Anurag M. and Banerjee, Rahul}
}
@article {47498,
	title = {Red fluorescent ultra-small gold nanoclusters functionalized with signal molecules to probe specificity in quorum sensing receptors in gram-negative bacteria},
	journal = {Archives of Microbiology},
	year = {2021},
	month = {JUN},
	type = {Article; Early Access},
	abstract = {Ultra-small (size < 2 nm) gold nanoclusters (AuNCs) are used as fluorescent probes which have excellent applications in bioimaging and sensing due to their emission in visible and NIR spectral region. Here, this property is exploited for understanding the quorum sensing phenomenon in bacteria which is regulated by signal molecules which are specific to various species. AuNCs are then functionalized with the signal molecules, Acyl Homoserine Lactones (AHL) of varying carbon chain length, C-6, C-8, and C-12 without 3rd C modification, to sense different strains of gram-negative bacteria i.e., Escherichia coli, Cronobacter sakazakii and Pseudomonas aeruginosa. In the concentration employed, selectivity to a limited extent is observed between the three Gram-negative bacteria tested. E. coli showed emission with all the AHL conjugates and P. aeruginosa did not interact with any of the three conjugates, whereas C. sakazakii showed specificity to C-8AHL. This is probably due to selectivity for cognate AHL molecules of appropriate concentrations.},
	keywords = {acyl homoserine lactone, fluorescence imaging, Gold nanoclusters, quorum sensing, Receptors, selectivity},
	issn = {0302-8933},
	doi = {10.1007/s00203-021-02338-y, Early Access Date = JUN 2021},
	author = {Chahande, Anurag M. and Lathigara, Disha and Prabhune, Asmita A. and Devi, R. Nandini}
}
@article {49350,
	title = {Ultra-small Au nanoclusters with tailored photoluminescence properties using modified thiol ligands: a computational and experimental demonstration},
	journal = {Particle \& Particle Systems Characterization},
	volume = {41},
	year = {2024},
	month = {OCT},
	type = {Article},
	abstract = {<p>
	Au nanoclusters with tailored photoluminescence can be obtained through controlled nanoparticle ligand interface chemistry. The present work reports molecular gold nanoclusters with tuneable photoluminescence emission from 600 to 700 nm using N,N {\textquoteleft},N {\textquoteleft}{\textquoteright}-trialkyl (11-mercaptoundecyl)ammonium chloride ligands as capping-agents. The tunability within red spectral region is regulated through specific interface chemistry between gold nanoclusters of molecular range and functional groups of the quaternary ammonium head over N,N {\textquoteleft},N {\textquoteleft}{\textquoteright}-trialkyl(11-mercaptoundecyl)ammonium chloride. Combined understanding obtained from the spectroscopy, microscopy, and density functional theory studies demonstrate that the functional group specific electronic interactions at the interfaces steer the emission characteristics of {\textquoteleft}{\textquoteleft}molecular{\textquoteright}{\textquoteright} Au nanoparticles. The study clearly identifies that bulkier functional groups, i.e., triethyl, tripropyl, tributyl, and dimethyl benzene over N+ (of thiol ligand) through their steric effects minimize the particle size giving rise to tunable photoluminescence emission in red spectral region. However, the red shift seen in the emission Au nanoclusters with N-(11-mercaptoundecyl)-N,N {\textquoteleft}-dimethylbenzenammonium chloride ligand in contradiction to particle size effect is computationally proved to be due to the delocalization of electron density from benzene aromatic ring to N+ of ammonium head leading to a reduction in the HOMO-LUMO energy gap. Fluorescence properties of water dispersible Au nanoclusters are tuned by varying the ammonium head group. Density Functional Theory studies correlate the distinction in emission when head group is phenyl to charge transfer characteristics. image</p>
},
	keywords = {Density functional theory, photoluminescent Au nanoclusters, surface plasmon resonance, thiol ligand},
	issn = {0934-0866},
	doi = {10.1002/ppsc.202400011},
	author = {Chahande, Anurag M. and Maibam, Ashakiran and Krishnamurty, Sailaja and Devi, R. Nandini}
}
