Linked Life Data

21366220

Source:http://linkedlifedata.com/resource/pubmed/id/21366220

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2011-3-30
pubmed:abstractText
We report on the fabrication of core cross-linked (CCL) micelles possessing thermoresponsive cores and their application as sensitive and selective ratiometric Hg(2+) probes with thermo-tunable detection efficiency. Well-defined double hydrophilic block copolymer (DHBC) bearing naphthalimide-based Hg(2+)-reactive moieties (NUMA, 4), PEO-b-P(NIPAM-co-NAS-co-NUMA), was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, where PEO, NIPAM, and NAS represent poly(ethylene oxide), N-isopropylacrylamide, and N-acryloxysuccinimide. At 25 °C, PEO-b-P(NIPAM-co-NAS-co-NUMA) unimers in aqueous solution can act as ratiometric Hg(2+) probes with a detection limit of ?10.1 nM. After core cross-linking of the micellar nanoparticles formed at elevated temperatures, structurally stable CCL micelles with well-solvated PEO coronas and thermoresponsive cores embedded with Hg(2+)-reactive NUMA moieties were obtained. Upon Hg(2+) addition, the aqueous dispersion of CCL micelles exhibit a colorimetric transition from yellowish to colorless and a fluorometric emission transition from green to bright blue. Moreover, Hg(2+) detection limits of CCL micelles were considerably enhanced to 3.0 and 1.8 nM at 25 and 40 °C, when the thermoresponsive cores are at their swollen and collapsed state, respectively. The high selectivity of CCL micelles to Hg(2+) over other common cations was also demonstrated. Furthermore, in vitro studies revealed that CCL micelles can effectively enter into living cells and sensitively respond to the presence of Hg(2+) ions via the change of fluorescence emission color. This work represents the first example of DHBC-based CCL micelle acting as highly selective and sensitive ratiometric metal ion probes. The structural stability, water dispersibility, biocompatibility, and most importantly the thermo-tunable detection sensitivity of this novel type of CCL micelle-based sensing systems augur well for their future applications as multifunctional nanocarriers for drug delivery, sensing, imaging, and diagnosis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1520-5827
pubmed:author
pubmed:issnType
Electronic
pubmed:day
5
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4082-90
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Thermoresponsive core cross-linked micelles for selective ratiometric fluorescent detection of Hg2+ ions.
pubmed:affiliation
CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't