Biomaterial Database

Detection of lead (II) with a "turn-on" fluorescent biosensor based on energy transfer from CdSe/ZnS quantum dots to graphene oxide. 2013

Ming Li, and Xuejiao Zhou, and Shouwu Guo, and Nianqiang Wu

Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506-6106, USA.

Graphene oxide (GO) sheets are mixed with the aptamer-functionalized CdSe/ZnS quantum dots (QDs). Consequently, the aptamer-conjugated QDs bind to the GO sheets to form a GO/aptamer-QD ensemble, which enables the energy transfer from the QDs to the GO sheets, quenching the fluorescence of QDs. The GO/aptamer-QD ensemble assay acts as a "turn-on" fluorescent sensor for Pb(2+) detection. When Pb(2+) ions are present in the assay, the interaction of Pb(2+) with the aptamer induces a conformational change in the aptamer, leading to the formation of a G-quadruplex/Pb(2+) complex. As a result, the QDs that are linked to the G-quadruplex/Pb(2+) complex are detached from the GO sheet, which "turns on" the fluorescence of the QDs. This sensor exhibits a limit of detection of 90pM and excellent selectivity toward Pb(2+) over a wide range of metal ions. The experiments have provided direct evidence that the fluorescence of QDs is quenched by GO via the nano-metal surface energy transfer (NSET) mechanism rather than the conventional Förster resonance energy transfer (FRET) process.

UI	MeSH Term	Description	Entries
D007854	Lead	A soft, grayish metal with poisonous salts; atomic number 82, atomic weight 207.2, symbol Pb.
D010087	Oxides	Binary compounds of oxygen containing the anion O(2-). The anion combines with metals to form alkaline oxides and non-metals to form acidic oxides.	Oxide
D004867	Equipment Design	Methods and patterns of fabricating machines and related hardware.	Design, Equipment,Device Design,Medical Device Design,Design, Medical Device,Designs, Medical Device,Device Design, Medical,Device Designs, Medical,Medical Device Designs,Design, Device,Designs, Device,Designs, Equipment,Device Designs,Equipment Designs
D006108	Graphite	An allotropic form of carbon that is used in pencils, as a lubricant, and in matches and explosives. It is obtained by mining and its dust can cause lung irritation.	Graphene
D013440	Sulfides	Chemical groups containing the covalent sulfur bonds -S-. The sulfur atom can be bound to inorganic or organic moieties.	Sulfide,Thioether,Thioethers,Sulfur Ethers,Ethers, Sulfur
D015374	Biosensing Techniques	Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.	Bioprobes,Biosensors,Electrodes, Enzyme,Biosensing Technics,Bioprobe,Biosensing Technic,Biosensing Technique,Biosensor,Electrode, Enzyme,Enzyme Electrode,Enzyme Electrodes,Technic, Biosensing,Technics, Biosensing,Technique, Biosensing,Techniques, Biosensing
D045663	Quantum Dots	Nanometer sized fragments of semiconductor crystalline material which emit PHOTONS. The wavelength is based on the quantum confinement size of the dot. They can be embedded in MICROBEADS for high throughput ANALYTICAL CHEMISTRY TECHNIQUES.	Nanocrystals, Semiconductor,Semiconductor Nanocrystals,Semiconductor Nanoparticles,Dot, Quantum,Dots, Quantum,Nanocrystal, Semiconductor,Nanoparticle, Semiconductor,Nanoparticles, Semiconductor,Quantum Dot,Semiconductor Nanocrystal,Semiconductor Nanoparticle
D017967	Zinc Compounds	Inorganic compounds that contain zinc as an integral part of the molecule.	Compounds, Zinc
D018036	Selenium Compounds	Inorganic compounds that contain selenium as an integral part of the molecule.	Compounds, Selenium
D019187	Cadmium Compounds	Inorganic compounds that contain cadmium as an integral part of the molecule.	Compounds, Cadmium