A label-free fluorescent probe for Hg2+ and biothiols based on graphene oxide and Ru-complex
A novel, selective and sensitive switch-on fluorescent sensor for Hg 2+ and switch-off fluorescent probe for biothiols was developed by using [Ru(bpy) 2 (pip)] 2+ as the signal reporter and graphene oxide (GO) as the quencher. Due to the affinity of GO towards single-stranded DNA (ss-DNA) and [Ru(bp...
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Published in | Scientific reports Vol. 4; no. 1; p. 5320 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group UK
17.06.2014
Nature Publishing Group |
Subjects | |
Online Access | Get full text |
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Summary: | A novel, selective and sensitive switch-on fluorescent sensor for Hg
2+
and switch-off fluorescent probe for biothiols was developed by using [Ru(bpy)
2
(pip)]
2+
as the signal reporter and graphene oxide (GO) as the quencher. Due to the affinity of GO towards single-stranded DNA (ss-DNA) and [Ru(bpy)
2
(pip)]
2+
, the three components assembled, resulting in fluorescence quenching. Upon addition of Hg
2+
, a double-stranded DNA (ds-DNA) via T–Hg
2+
–T base pairs was formed and [Ru(bpy)
2
(pip)]
2+
intercalated into the newly formed ds-DNA. Then, [Ru(bpy)
2
(pip)]
2+
and ds-DNA were removed from the surface of GO, resulting in the restoration of fluorescence. Subsequently, upon addition of biothiols, Hg
2+
was released from ds-DNA, due to the higher affinity of Hg
2+
to the sulfur atoms of biothiols, which could induce ds-DNA unwinding to form ss-DNA. Then ss-DNA and [Ru(bpy)
2
(pip)]
2+
were adsorbed on the surface of GO, the fluorescence of [Ru(bpy)
2
(pip)]
2+
was quenched again. Therefore, the changes in emission intensity of [Ru(bpy)
2
(pip)]
2+
directly correlated to the amount of detection target (Hg
2+
or biothiols) in solution. The assay exhibited high sensitivity and selectivity, with the limits of detection for Hg
2+
, cysteine (Cys) and glutathione (GSH) to be 2.34 nM, 6.20 nM and 4.60 nM, respectively. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2045-2322 2045-2322 |
DOI: | 10.1038/srep05320 |