Visual detection and removal of mercury ions by a ferrocene derivative

Novel mesoporous organosilica nanoparticles with ferrocene group for efficient removal of contaminants from wastewater

Traditional method to functionalize mesoporous silica nanoparticles with organic groups for removal of contaminants from wastewater was surface modification. However, this surface modification could not cover the entire surface, leading to incomplete utilization of the high surface area of MSNs. In this work, we designed and prepared a novel inorganic-organic hybrid nanomaterial: ferrocene incorporated mesoporous organosilica nanoparticles (MONs). Owing to the mesoporous structure, large surface area and the ferrocene group in the framework, MONs could adsorb phosphate anion more efficiently with adsorption capacities up to 1299 mg/g than surface modified MSNs (SiO₂-Fe) (488 mg/g). Congo red (CR) and Pb²⁺ were also used as the model contaminants, and the results indicated that MONs is a superior absorbent comparing with ferrocene surface modified MSNs.

Fluorescence quenching of MoS2 nanosheets/DNA/silicon dot nanoassembly: effective and rapid detection of Hg2+ ions in aqueous solution

Mercury (Hg) contamination of aquatic sites represents a serious risk for human health and the environment. Therefore, effective and rapid monitoring of Hg in aqueous samples is a challenge of timely importance nowadays. In the present study, a rapid and sensitive mercury sensor based on the fluorescence quenching of MoS₂ nanosheets/DNA/silicon dot nanoassembly has been developed for the efficient detection of mercury(II) in aquatic environments. In this process, silicon dots were synthesized through one-step high-temperature calcinations and thermomagnesium reduction method at 900 °C using rice husk as a silicon source, which demonstrates superior photophysical properties and excitation-dependent fluorescence behavior. The interaction between MoS₂ nanosheets/DNA/silicon dot nanoassembly and Hg²⁺ ions was studied using photoluminescence spectroscopy. The addition of Hg²⁺ ions to the assay solution induced the detachment of fluorescent probe from the surface of MoS₂ nanosheets. Thus, the fluorescent probes sustained its fluorescence intensity. The developed sensor was tested on various concentrations of Hg²⁺ ions ranging from 0 to 1000 nM as well as on various metal ions. In addition, MoS₂ nanosheets/DNA/silicon dot nanoassembly fluorescent Hg sensor efficiently detected the presence of Hg²⁺ ions in real-time water samples, which was comparably detected by the conventional atomic absorbance spectrometer (AAS). Overall, our results highlighted the high reliability of the present approach for environmental monitoring of Hg²⁺ ions, if compared to that of the customary method with a lowest detection limit of 0.86 nM.

Synthesis and characterization of a bifunctional nanoprobe for CGG trinucleotide repeat detection

A novel bifunctional nanoprobe was designed and used in an electrochemical sensor to rapidly detect CGG trinucleotide repeats.