{'fraction_non_alphanumeric': 0.02675059008654603, 'fraction_numerical': 0.012588512981904013, 'mean_word_length': 5.456852791878172, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Silica-Coated Mn-Doped ZnS Nanocrystals for Cancer Theranostics

Doped
nanocrystals such as manganese-doped zinc sulfide (ZnS:Mn)
are useful nanomedicine probes for cancer cell labeling and anticancer
drug delivery. However, the synthesis and retention of fluorescence
of these nanocrystals is highly indispensable for efficient cell theranostics.
Herein, we report a modified synthesis of highly fluorescent hydrophobic
ZnS:Mn nanocrystals with the advent of dual ligands. Our results demonstrate
that the alkylamine ligand with the carbon chain length of C18 promotes the diffusion of Mn from the surface into the interior
of ZnS nanocrystals. Optical measurements show that the quantum yield
of Mn (QYMn) can reach as high as 80% in the presence of
a dual ligand combination of oleylamine–octadecylamine because
of the increased probability of 4T1 → 6A1 emission, originating from the energy transfer
of ligated nanocrystals. These doped nanocrystals after ligand exchange
of organic ligands with glutathione exhibited a high retention of
quantum yield (QY: ∼50–60%), and further coating with
silica showed the QY of ∼35–40%. Finally, we show the
application of these doped nanocrystals for cancer theranostics such
as HeLa cell labeling and anti-cancer drug delivery.