MilliporeSigma
  • Home
  • Search Results
  • Preparation of graphene quantum dots based core-satellite hybrid spheres and their use as the ratiometric fluorescence probe for visual determination of mercury(II) ions.

Preparation of graphene quantum dots based core-satellite hybrid spheres and their use as the ratiometric fluorescence probe for visual determination of mercury(II) ions.

Analytica chimica acta (2015-09-01)
Mengjuan Hua, Chengquan Wang, Jing Qian, Kan Wang, Zhenting Yang, Qian Liu, Hanping Mao, Kun Wang
ABSTRACT

We herein proposed a simple and effective strategy for preparing graphene quantum dots (GQDs)-based core-satellite hybrid spheres and further explored the feasibility of using such spheres as the ratiometric fluorescence probe for the visual determination of Hg(2+). The red-emitting CdTe QDs were firstly entrapped in the silica nanosphere to reduce their toxicity and improve their photo and chemical stabilities, thus providing a built-in correction for environmental effects, while the GQDs possessing good biocompatibility and low toxicity were electrostatic self-assembly on the silica surface acting as reaction sites. Upon exposure to the increasing contents of Hg(2+), the blue fluorescence of GQDs can be gradually quenched presumably due to facilitating nonradiative electron/hole recombination annihilation. With the embedded CdTe QDs as the internal standard, the variations of the tested solution display continuous fluorescence color changes from blue to red, which can be easily observed by the naked eye without any sophisticated instrumentations and specially equipped laboratories. This sensor exhibits high sensitivity and selectivity toward Hg(2+) in a broad linear range of 10 nM-22 μM with a low detection limit of 3.3 nM (S/N = 3), much lower than the allowable Hg(2+) contents in drinking water set by U.S. Environmental Protection Agency. This prototype ratiometric probe is of good simplicity, low toxicity, excellent stabilities, and thus potentially attractive for Hg(2+) quantification related biological systems.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
VenPure® SF, powder
Sigma-Aldrich
Ammonia-14N, 99.99 atom % 14N
Sigma-Aldrich
Tellurium, pieces, 99.999% trace metals basis
Sigma-Aldrich
Tellurium, granular, −5-+50 mesh, 99.99% trace metals basis
Sigma-Aldrich
Tellurium, shot, 1-2 mm, 99.999% trace metals basis
Sigma-Aldrich
Tellurium, powder, −200 mesh, 99.8% trace metals basis
Sigma-Aldrich
Sodium borohydride solution, 2.0 M in triethylene glycol dimethyl ether
Sigma-Aldrich
Sodium borohydride solution, 0.5 M in 2-methoxyethyl ether
Sigma-Aldrich
Tellurium, powder, −30 mesh, 99.997% trace metals basis
Sigma-Aldrich
Sodium borohydride solution, ~12 wt. % in 14 M NaOH
Sigma-Aldrich
Ammonia, anhydrous, ≥99.98%
Sigma-Aldrich
Ammonia solution, 0.4 M in THF
Sigma-Aldrich
Ammonia solution, 4 M in methanol
Sigma-Aldrich
Ethanol Fixative 80% v/v, suitable for fixing solution (blood films)
Sigma-Aldrich
Water, sterile-filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
Water, deuterium-depleted, ≤1 ppm (Deuterium oxide)
Sigma-Aldrich
Water, for embryo transfer, sterile-filtered, BioXtra, suitable for mouse embryo cell culture
Sigma-Aldrich
E-Toxate Water, endotoxin, free
Sigma-Aldrich
Water, Nuclease-Free Water, for Molecular Biology
Sigma-Aldrich
Water, for cell biology, sterile ultrafiltered
Supelco
Ethanol standards 10% (v/v), 10 % (v/v) in H2O, analytical standard
Sigma-Aldrich
Water, for molecular biology, sterile filtered
Sigma-Aldrich
Water, PCR Reagent
Sigma-Aldrich
Water, BioPerformance Certified
Sigma-Aldrich
Sodium borohydride, caplets (18 × 10 × 8 mm), 98%
Sigma-Aldrich
Sodium borohydride, granular, 99.99% trace metals basis
Sigma-Aldrich
Sodium borohydride, granular, 10-40 mesh, 98%
Sigma-Aldrich
Sodium borohydride, ReagentPlus®, 99%
Sigma-Aldrich
Sodium borohydride, purum p.a., ≥96% (gas-volumetric)
Sigma-Aldrich
Sodium borohydride, hydrogen-storage grade, 98%