01261nas a2200217 4500008004100000022001400041245014200055210006900197260007700266300001200343490000700355520041700362653001500779653001800794653002600812653002800838653001300866100001900879700001700898856012800915 2014 eng d a0934-086600aBlue luminescent graphene quantum dots by photochemical stitching of small aromatic molecules: fluorescent nanoprobes in cellular imaging0 aBlue luminescent graphene quantum dots by photochemical stitchin aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR a433-4380 v313 a

Blue fluorescent graphene quantum dots (GQDs) are synthesized from small haloaromatic molecules by laser photochemistry. The process involves a bottom-up photochemical stitching mechanism of the free radicals generated by irradiation of ultraviolet photons (lambda = 248 nm) on o-dichlorobenzene. The GQDs are further demonstrated to be of importance as fluorescent nanoprobes in bioimaging of cells.image

10abioimaging10afree radicals10agraphene quantum dots10aphotochemical stitching10aUV laser1 aGokhale, Rohan1 aSingh, Pooja uhttp://library.ncl.res.in/content/blue-luminescent-graphene-quantum-dots-photochemical-stitching-small-aromatic-molecules-002562nas a2200265 4500008004100000022001400041245013200055210006900187260000900256300001000265490000700275520167700282653001801959653001501977653002201992653002702014653001302041100002202054700002102076700001602097700002402113700001702137700002202154856012002176 2015 eng d a0920-506300aFluorescent cadmium telluride quantum dots embedded chitosan nanoparticles: a stable, biocompatible preparation for bio-imaging0 aFluorescent cadmium telluride quantum dots embedded chitosan nan cJAN  a42-560 v263 a

Fluorescent cadmium telluride quantum dots (CdTe QDs) are an optically attractive option for bioimaging, but are known to display high cytotoxicity. Nanoparticles synthesized from chitosan, a natural biopolymer of beta 1-4 linked glucosamine, display good biocompatibility and cellular uptake. A facile, green synthetic strategy has been developed to embed green fluorescent cadmium telluride quantum dots (CdTe QDs) in biocompatible CNPs to obtain a safer preparation than `as is' QDs. High-resolution transmission electron microscopy showed the crystal lattice corresponding to CdTe QDs embedded in CNPs while thermogravimetry confirmed their polymeric composition. Electrostatic interactions between thiol-capped QDs (4nm, -57mV) and CNPs (\~300nm, +38mV) generated CdTe QDs-embedded CNPs that were stable up to three months. Further, viability of NIH3T3 mouse fibroblast cells in vitro increased in presence of QDs-embedded CNPs as compared to bare QDs. At the highest concentration (10 mu g/ml), the former shows 34 and 39% increase in viability at 24 and 48h, respectively, as compared to the latter. This shows that chitosan nanoparticles do not release the QDs up to 48h and do not cause extended toxicity. Furthermore, hydrolytic enzymes such as lysozyme and chitinase did not degrade chitosan nanoparticles. Moreover, QDs-embedded CNPs show enhanced internalization in NIH3T3 cells as compared to bare QDs. This method offers ease of synthesis and handling of stable, luminescent, biocompatible CdTe QDs-embedded CNPs with a favorable toxicity profile and better cellular uptake with potential for bioimaging and targeted detection of cellular components.

10aBiocompatible10abioimaging10aCdTe quantum dots10achitosan nanoparticles10aToxicity1 aGhormade, Vandana1 aGholap, Haribhau1 aKale, Sonia1 aKulkarni, Vaishnavi1 aBhat, Suresh1 aPaknikar, Kishore uhttp://library.ncl.res.in/content/fluorescent-cadmium-telluride-quantum-dots-embedded-chitosan-nanoparticles-stable02262nas a2200169 4500008004100000245015100041210006900192260000800261300001400269490000600283520159700289653002101886653001501907100002701922700001701949856012601966 2017 eng d00api-Conjugated chromophore incorporated polystyrene nanobeads as single optical agent for three-channel fluorescent probe in bioimaging application0 apiConjugated chromophore incorporated polystyrene nanobeads as s cAUG a1788-17980 v33 a

Fluorescent polystyrene (PS) nanobeads in the size range similar to 70-120 nm incorporating perylene bisimide (PBI-PS) and/or oligo(p-phenylenevinylene) (OPV-PS) was developed by miniemulsion polymerization technique. A dye loading content (DLC) of <3% was sufficient to impart high fluorescence emission capability to the PS beads. OPV-PS exhibited emission in the range 400-550 nm with peak emission at 450 nm (lambda(ex) = 350 nm; phi(FL) = 26%); PBI-PS showed emission from 520-650 nm with peak emission at 545 nm (lambda(ex) = 490 nm; phi(FL) = 9.7%) in 1x PBS buffer, whereas OPV(PBI)-PS nanobeads incorporating both the fluorophores exhibited multicolor emission capabilities (lambda(ex) from 350 to 490 nm). The nanoparticles were characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS) for size and zeta potential for surface charge. For bioimaging applications, the PS nanoparticles were incubated with HeLa cells. Cell viability analysis involving HeLa cells showed more than 90% cell viability confirming the biocompatibility of the PS The cellular uptake of the nanoparticles was confirmed by flow cytometry analysis and confocal laser scanning microscopy (CLSM) images. The subcellular localization of the nanoparticles in the cytoplasm could be precisely established by their simultaneous multicolor emission. The PS-based single optical agent presented here that can function as three-channel fluorescent probe to meet the requirements for multicolor bioimaging is advantageous.

10aBiocompatibility10abioimaging1 aMakkad, Sarabjot, Kaur1 aAsha, S., K. uhttp://library.ncl.res.in/content/pi-conjugated-chromophore-incorporated-polystyrene-nanobeads-single-optical-agent-three