A novel colorimetric probe with positive correlation between toxicity and the reaction for the assessment of chromium ions

Raspberry-Like Gold Nanoparticles Based On Nanoclusters Anchored on Cyclodextrin-Functionalized Nanoparticles: Synthesis and Ultrasensitive Electrochemical Detection of Chromium(VI) Ions

A facile synthetic strategy is devised to construct raspberry like gold nanoparticles (RbNPs) formed by gold nanoclusters wrapped around β-cyclodextrin functionalized gold nanoparticles (CD-AuNPs@AuNCs). An efficient and sensitive electrochemical sensor for the detection of Cr(VI) has been developed based on RbNPs. The sensing platform exhibits an excellent wide linear range (100 pg mL^-1 to 10 μg mL^-1 ), extremely low detection limit (40.91 fg mL^-1 i. e. 0.79 pM), which may pave a new way to fabricate other ultrasensitive electrochemical sensors based on the designed RbNPs.

One-pot synthesis of novel water-dispersible fluorescent silicon nanoparticles for selective Cr2O72- sensing

Chromium (Cr(vi)), a highly toxic metal-oxyanion which is carcinogenic and mutagenic to humans, is a severe environmental pollutant. Developing simple methods for sensitive and selective detection of Cr(vi) is of great significance. In this work, fluorescent silicon nanoparticles (SiNPs) with good water solubility were facilely synthesized via a one-step hydrothermal method by using (3-aminopropyl)triethoxysilane (APTES) as the silicon source and natural antioxidant quercetin as the reducing agent. The obtained SiNPs displayed good thermostability, salt-tolerance and photo-stability. The as-prepared SiNPs exhibited bright blue emission at 437 nm under excitation at 362 nm, allowing them to be developed as a fluorescent probe for detection of Cr2O72-. Significantly, the fluorescence of the SiNPs could be remarkably quenched by Cr2O72-via the internal filtering effect (IFE). Based on this phenomenon, a novel fluorescence method for detection of Cr2O72- was established. A good linear relationship was obtained from 0.5 to 100 μM with a limit of detection (based on 3 s/k, LOD) of 180 nM. The proposed fluorescence method was successfully applied to the detection of Cr2O72- in tap water. Moreover, a fluorescent filter paper sensor was developed for the visual detection of Cr2O72-, providing a valuable platform for Cr2O72- sensing in a convenient way.