Using silicon-coated gold nanoparticles to enhance the fluorescence of CdTe quantum dot and improve the sensing ability of mercury (II).

Title Using silicon-coated gold nanoparticles to enhance the fluorescence of CdTe quantum dot and improve the sensing ability of mercury (II).
Authors J. Zhu; H. Chang; J.J. Li; X. Li; J.W. Zhao
Journal Spectrochim Acta A Mol Biomol Spectrosc
DOI 10.1016/j.saa.2017.06.038
Abstract

The effect of silicon-coated gold nanoparticles with different gold core diameter and silica shell thickness on the fluorescence emission of CdTe quantum dots (QDs) was investigated. For gold nanoparticles with a diameter of 15nm, silica coating can only results in fluorescence recover of the bare gold nanoparticle-induced quenching of QDs. However, when the size of gold nanoparticle is increased to 60nm, fluorescence enhancement of the QDs could be obtained by silica coating. Because of the isolation of the silica shell-reduced quenching effect and local electric field effect, the fluorescence of QDs gets intense firstly and then decreases. The maximum fluorescence enhancement takes place as the silica shell has a thickness of 30nm. This enhanced fluorescence from silicon-coated gold nanoparticles is demonstrated for sensing of Hg(2+). Under optimal conditions, the enhanced fluorescence intensity decreases linearly with the concentration of Hg(2+) ranging from 0 to 200ng/mL. The limit of detection for Hg(2+) is 1.25ng/mL. Interference test and real samples detection indicate that the influence from other metal ions could be neglected, and the Hg(2+) could be specifically detected.

Citation J. Zhu; H. Chang; J.J. Li; X. Li; J.W. Zhao.Using silicon-coated gold nanoparticles to enhance the fluorescence of CdTe quantum dot and improve the sensing ability of mercury (II).. Spectrochim Acta A Mol Biomol Spectrosc. 2018;188:170178. doi:10.1016/j.saa.2017.06.038

Related Elements

Cadmium

See more Cadmium products. Cadmium (atomic symbol: Cd, atomic number: 48) is a Block D, Group 12, Period 5 element with an atomic weight of 112.411. Cadmium Bohr ModelThe number of electrons in each of Cadmium's shells is 2, 8, 18, 18, 2 and its electron configuration is [Kr]4d10 5s2. The cadmium atom has a radius of 151 pm and a Van der Waals radius of 230 pm. Cadmium was discovered and first isolated by Karl Samuel Leberecht Hermann and Friedrich Stromeyer in 1817. In its elemental form, cadmium has a silvery bluish gray metallic appearance. Cadmium makes up about 0.1 ppm of the earth's crust. Elemental CadmiumNo significant deposits of cadmium containing ores are known, however, it is sometimes found in its metallic form. It is a common impurity in zinc ores and is isolated during the production of zinc. Cadmium is a key component in battery production and particular pigments and coatings due to its distinct yellow color. Cadmium oxide is used in phosphors for television picture tubes. The name Cadmium originates from the Latin word 'cadmia' and the Greek word 'kadmeia'.

Gold

See more Gold products. Gold (atomic symbol: Au, atomic number: 79) is a Block D, Group 11, Period 6 element with an atomic weight of 196.966569. The number of electrons in each of Gold's shells is 2, 8, 18, 32, 18, 1 and its electron configuration is [Xe]4f142 5d10 6s1. Gold Bohr ModelThe gold atom has a radius of 144 pm and a Van der Waals radius of 217 pm. Gold was first discovered by Early Man prior to 6000 B.C. In its elemental form, gold has a metallic yellow appearance. Gold is a soft metal and is usually alloyed to give it more strength.Elemental Gold It is a good conductor of heat and electricity, and is unaffected by air and most reagents. It is one of the least reactive chemical elements. Gold is often found as a free element and with silver as a gold-silver alloy. Less commonly, it is found in minerals as gold compounds, usually with tellurium.

Silicon

See more Silicon products. Silicon (atomic symbol: Si, atomic number: 14) is a Block P, Group 14, Period 3 element with an atomic weight of 28.085. Silicon Bohr MoleculeThe number of electrons in each of Silicon's shells is 2, 8, 4 and its electron configuration is [Ne] 3s2 3p2. The silicon atom has a radius of 111 pm and a Van der Waals radius of 210 pm. Silicon was discovered and first isolated by Jöns Jacob Berzelius in 1823. Silicon makes up 25.7% of the earth's crust, by weight, and is the second most abundant element, exceeded only by oxygen. The metalloid is rarely found in pure crystal form and is usually produced from the iron-silicon alloy ferrosilicon. Elemental SiliconSilica (or silicon dioxide), as sand, is a principal ingredient of glass, one of the most inexpensive of materials with excellent mechanical, optical, thermal, and electrical properties. Ultra high purity silicon can be doped with boron, gallium, phosphorus, or arsenic to produce silicon for use in transistors, solar cells, rectifiers, and other solid-state devices which are used extensively in the electronics industry.The name Silicon originates from the Latin word silex which means flint or hard stone.

Tellurium

See more Tellurium products. Tellurium (atomic symbol: Te, atomic number: 52) is a Block P, Group 16, Period 5 element with an atomic radius of 127.60. Tellurium Bohr ModelThe number of electrons in each of tellurium's shells is 2, 8, 18, 18, 6 and its electron configuration is [Kr] 4d10 5s2 5p4. Tellurium was discovered by Franz Muller von Reichenstein in 1782 and first isolated by Martin Heinrich Klaproth in 1798. In its elemental form, tellurium has a silvery lustrous gray appearance. The tellurium atom has a radius of 140 pm and a Van der Waals radius of 206 pm. Elemental TelluriumTellurium is most commonly sourced from the anode sludges produced as a byproduct of copper refining. The name Tellurium originates from the Greek word Tellus, meaning Earth.

Mercury

Mercury Bohr ModelSee more Mercury products. Mercury (atomic symbol: Hg, atomic number: 80) is a Block D, Group 12, Period 6 element with an atomic weight of 200.59. The number of electrons in each of mercury's shells is 2, 8, 18,32, 18, 2 and its electron configuration is [Xe] 4f14 5d10 6s2. The mercury atom has a radius of 151 pm and a Van der Waals radius of 209 pm. It is named after the planet Mercury and often referred to as "quicksilver" due to its appearance as a silvery liquid. Mercury has low melting and boiling points. It is a poor conductor of heat, but a fair conductor of electricity. Mercury is found both as a free element and in cinnabar, corderoite, and livingstonite ores.

Related Forms & Applications