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Highly sensitive and selective label-free optical detection of mercuric ions using photon upconverting nanoparticles.

ABSTRACT: We demonstrate a fluorescence-based, label-free detection scheme that reports the presence of Hg(II) ion using photon upconverting nanoparticles. A single-stranded DNA containing a number of thymine bases to be used as the Hg(2+)-capturing element is covalently attached to the photon upconverting NaYF(4):Yb(3+),Tm(3+) nanoparticles. Under the illumination of 980 nm laser, energy transfer takes place between the NaYF(4):Yb(3+),Tm(3+) nanoparticles as the donor and SYBR Green I, a DNA intercalating dye, as the acceptor. By monitoring the ratio of the acceptor emission to the donor emission, we can quantitatively detect the presence of the mercuric ions with a directly observed detection limit of 0.06 nM. The remarkably high signal-to-noise ratio of photon upconverting particles leads to very high sensitivity and specificity without the need of fluorophore labeling. The sensor also does not suffer from photobleaching.

SUBMITTER: Kumar M

PROVIDER: S-EPMC2880226 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature

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Highly sensitive and selective label-free optical detection of mercuric ions using photon upconverting nanoparticles.

Kumar Manoj M Zhang Peng P

Biosensors & bioelectronics 20100407 11

We demonstrate a fluorescence-based, label-free detection scheme that reports the presence of Hg(II) ion using photon upconverting nanoparticles. A single-stranded DNA containing a number of thymine bases to be used as the Hg(2+)-capturing element is covalently attached to the photon upconverting NaYF(4):Yb(3+),Tm(3+) nanoparticles. Under the illumination of 980 nm laser, energy transfer takes place between the NaYF(4):Yb(3+),Tm(3+) nanoparticles as the donor and SYBR Green I, a DNA intercalatin ...[more]

PMID: 20456935

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