Molecularly Engineered Quantum Dots for Visualization of Hydrogen Sulfide

Abstract

Among various fluorescence nanomaterials, the II-VI semiconductor nanocrystals (usually called quantum dots, QDs) should be very promising in sensing application because of their high quantum yields, capability for surface property manipulation, and unlimited possible chemical reactions. Herein, we present a fluorescence probe for hydrogen sulfide, which was prepared by first encapsulating inorganic cadmium telluride (CdTe) QDs in silica nanospheres, and subsequently engineering the silica surface with functional molecules azidocoumarin-4-acetic acid reactive to hydrogen sulfide. The nanohybrid probe exhibited two fluorescence bands centered at 452 and 657 nm, respectively. The red fluorescence at 657 nm of the nanohybrid probe is stable against H2S, while the blue fluorescence is specifically sensitive to H2S. The probe showed a distinct fluorescence color evolution from light magenta to blue upon exposure to different amounts of H2S, and a detection limit of 7.0 nM was estimated in aqueous solution. We further applied the nanohybrid probe for visual detection of gaseous H2S with a low concentration of 0.5 ppm using glass indicating spots sensors, suggesting its potential application for gaseous H2S sensing. Such an efficient on-site visual determination of gaseous hydrogen sulfide (H2S) is highly demanded in on-site environmental monitoring and protection.

Functionalized calcium silicate nanofibers with hierarchical structure derived from oyster shells and their application in heavy metal ions removal

“…Cd 2+ , Cu 2+ , Pb 2+ , Hg 2+ , Cr 2 O 7 2À , MnO 4 À and AsO 4 3À ) have posed a major environmental health risk worldwide, 1-3 and the exploration of techniques for the removal of these ions has been receiving increasing attention. [5][6][7]14,18,20 Notwithstanding these advances, the fabrication and application of adsorbents still frequently suffer from low capacity, high cost, and/or difficulties in the regeneration and reuse of sorbents. is considered to be one of the most promising technologies for environmental remediation.…”

Metal oxides and metal salt nanostructures for hydrogen sulfide sensing: mechanism and sensing performance

“…In the past, many quantum dot, metal nanoparticles and organic dyes have been utilized in the gas detection including the reducing gas H 2 S. [28][29][30][31][32][33][34][35][36] These sensors are mostly based on the optical properties of the materials as a sensing signal. The optical signal undoubted provides sensitive and naked eye approach to the gas recognition.…”

A turn-on fluorescent probe with a dansyl fluorophore for hydrogen sulfide sensing

“…19 Compared to these methods, uorescence analysis has proven to be a promising option because of its high sensitivity, high temporal and spatial detection resolutions, and the ability for conducting in situ monitoring of reactive and transient target analytes. [20][21][22][23][24][25][26][27] Generally, the uorescence probes for H 2 S mainly based on reduction reactions, [28][29][30][31][32] nucleophilic addition reactions, [33][34][35] and thiolysis reactions. [36][37][38] In addition, metal displacement approach utilizes the strong affinity of metal ions with suldes ions to rapidly attain reaction equilibrium, and achieve the realtime detection of H 2 S. 39,40 Based on metal displacement approach of copper metal complexes, some colorimetric or uorescent sensors for H 2 S have been emerging in recent years, owning to the low solubility product of CuS (K sp ¼ 6.3 Â 10 À36 ).…”