Dual-color determination of protein via terminal protection of small-molecule-linked DNA and the enzymolysis of exonuclease III.
We have developed a new dual-color fluorescent biosensor for protein detection based on terminal protection of small-molecule-linked DNA and the enzymolysis of exonuclease III (Exo III). The determination of streptavidin (SA) was realized via fluorescence signals of the green color from quantum dots (QDs) and the red from [Ru(phen)2(dppx)](2+). In the absence of SA, biotin-DNA was degradated by the Exo III, thus making the [Ru(phen)2(dppx)](2+) employed as a fluorescence quencher to the QDs. With the addition of SA, dual-color response appeared because of the specific binding between SA and biotin so that the biotin-dsDNA was protected and combined with [Ru(phen)2(dppx)](2+), leading to the QDs recovery and the generating of [Ru(phen)2(dppx)](2+) fluorescence. This sensor exhibited high sensitivity with a low detection limit (2.11ng/mL) and firstly introduced dual-color QDs-ruthenium complex dyads to protein assay.
['Chen|Chaohui|C|', 'Xiang|Xia|X|', 'Liu|Yufei|Y|', 'Zhou|Guohua|G|', 'Ji|Xinghu|X|', 'He|Zhike|Z|']
D015374:Biosensing Techniques D002384:Catalysis D003124:Colorimetry D004247:DNA D004268:DNA-Binding Proteins D004867:Equipment Design D019544:Equipment Failure Analysis D005090:Exodeoxyribonucleases D011485:Protein Binding D025941:Protein Interaction Mapping D013050:Spectrometry, Fluorescence
Dual-color Terminal protection of small-molecule-linked DNA Protein detection QDs [Ru(phen)(2)(dppx)](2+)