| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1229442 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2015 | 7 Pages |
•ZnS:Mn nanocrystals were synthesized using chitosan and various amino acid ligands.•The PL emission intensity of l-citrulline capped ZnS:Mn is found to be maximum.•ZnS:Mn capped with l-citrulline is more effective as a fluorescent probe.•ZnS:Mn capped with l-citrulline is assessed to be less toxic.•ZnS:Mn capped with l-arginine has maximum uptake in HEK293T cells.
Highly luminescent, manganese doped, zinc sulphide (ZnS:Mn) nanocrystals biofunctionalized with chitosan and various aminoacids such as l-citrulline, l-lysine, l-arginine, l-serine, l-histidine and glycine were synthesized by chemical capping co-precipitation method at room temperature, which is a simple and cost effective technique. The synthesized nanocrystals were structurally characterized by TEM, XRD, EDXS and FT-IR spectroscopy techniques. They possess high colloidal stability with strong orange red photoluminescence emission at 598 nm. The intensity of orange red emission has been observed to be maximum in l-citrulline capped ZnS:Mn nanocrystals in which the emission at 420 nm is effectively quenched by surface passivation due to capping. Taking into consideration the prospects of these highly luminescent, bio-compatible ZnS:Mn nanocrystals in bio-imaging applications, cytotoxicity studies were conducted to identify the capping combination which would accomplish minimum toxic effects. ZnS:Mn nanocrystals biofunctionalized with chitosan, l-citrulline, glycine, l-artginine, l-serine and l-histidine showed least toxicity up to 10 nM concentrations in mouse fibroblast L929 cells, which further confirms their cytocompatibility. Also the ZnS:Mn nanocrystals biofunctionalized with l-arginine showed maximum uptake in in vitro studies carried out in human embryonic kidney cells, HEK-293T, which shows the significant role of this particular amino acid in fetoplacental nutrition. The present study highlights the suitability of aminoacid conjugated ZnS:Mn nanocrystals, as promising candidates for biomedical applications.
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