A single-molecular ruthenium(II) complex-based NIR-II fluorophore for enhanced chemo-photothermal therapy.

Novel NIR-II Ru(II) polypyridyl fluorophore Ru-1 dots for synergistic chemo-photothermal therapy against 4T1 tumors were designed and synthesized. Guided by in vivo NIR-II fluorescence imaging, the synergistic therapeutic efficacy, intracellular delivery, and biodistribution of the Ru-1 dots were precisely tracked in real-time.

Ratiometric Fluorescence Detection of DNA Based on the Inner Filter Effect of Ru(bpy)2(dppx)2+ toward Silicon Nanodots.

A ratiometric DNA sensor was developed based on fluorescent silicon nanodots (SiNDs) and Ru(bpy)2(dppx)2+. The absorption spectrum of Ru(bpy)2(dppx)2+ has significant overlap with both the excitation and emission spectra of SiNDs. Therefore, fluorescence quenching of Ru(bpy)2(dppx)2+ toward SiNDs can occur on account of the strong inner filter effect. The effect of quenching is not influenced by the specific binding between Ru(bpy)2(dppx)2+ and DNA. Fluorescence turn-on detection of DNA can be performed employing Ru(bpy)2(dppx)2+ and SiNDs as the response and reference signals, respectively. Using SiND-Ru(bpy)2(dppx)2+, a convenient, sensitive, rapid, and precise method could be developed for DNA detection. In aqueous solutions, the I 601/I 448 fluorescence intensity ratio of SiND-Ru(bpy)2(dppx)2+ increases linearly in the DNA concentration range of 20-1500 nM. The limit of detection and precision of the method is 4.3 nM and 3.5% (50 nM, n = 13), respectively. The ratiometric sensor was tested for visual detection of trace DNA. Moreover, this method was found suitable for the ratiometric detection of DNA in a simulated sample and a human serum sample, and the recoveries were in the range of 98-119%.

Fe3O4 nanoparticles coated with double imprinted polymers for magnetic solid phase extraction of lead(II) from biological and environmental samples.

Double imprinted polymer coated magnetic nanoparticles were fabricated with 4-nm size ZnO nanoparticles acting as the sacrifice templates, which were co-imprinted with template Pb(II) ions. After template removal, abundant transfer pores derived from ZnO nanoparticles were left around the selective adsorption sites derived from Pb(II) ions. The magnetic sorbent exhibit good selectivity, rapid adsorption kinetic and large adsorption capacity for Pb(II). They were used to extract trace Pb(II) followed by graphite furnace atomic absorption spectrometry detection. After the optimization of extraction conditions, following merits are found: (a) rapid extraction (10 min), (b) high preconcentration factor (100 fold), (c) sensitive detection with the detection limit of 9.4 ng·L-1, and (d) low relative standard deviation (6.9%) at a level of 50 ng·L-1 of Pb(II) analyzed 7 times. The method was employed in extraction and quantification of trace Pb in biological and environmental samples with satisfactory recoveries of 87.5-104%. Graphical abstractDouble imprinted polymer coated magnetic nanoparticles (MNPs@DIP) were fabricated and used for extraction of Pb(II) followed by graphite furnace atomic absorption spectrometry (GFAAS) detection. The method was successfully applied for the determination of Pb in environmental and biological samples.

Ligand-assisted magnetic solid phase extraction for fast speciation of silver nanoparticles and silver ions in environmental water.

In this work, poly(1-vinylimidazole) functionalized magnetic nanoparticles (PVIM-MNPs) were prepared and adopted for the adsorption of silver nanoparticles (AgNPs) and silver ions (Ag ions). With the use of mercaptosuccinic acid as a ligand exchanger, both of AgNPs and Ag ions could be adsorbed on the PVIM-MNPs and the sequential desorption of Ag ions and AgNPs was easily achieved by using Na2S2O3 and HNO3, respectively. Based on it, a new approach by coupling ligand-assisted magnetic solid phase extraction (MSPE) with graphite furnace atomic absorption spectrometry (GFAAS) detection was proposed for the speciation of AgNPs and Ag ions in environmental water samples. Factors affecting MSPE of AgNPs and Ag ions were investigated and the optimized conditions were established. With an enrichment factor of 100-fold, the detection limits of the proposed method were 7.5 and 8.2 ng L-1 for Ag ions and AgNPs with relative standard deviations of 6.4% and 7.0% (c = 50 ng L-1, n = 7), respectively. The proposed ligand-assisted MSPE-GFAAS method has the advantages of high sensitivity, low cost and easy operation, and could be used for the quantification of Ag ions and various coating modified AgNPs with a size range of 5-120 nm in environmental waters.

Advanced functional materials in solid phase extraction for ICP-MS determination of trace elements and their species - A review.

For the determination of trace elements and their species in various real samples by inductively coupled plasma mass spectrometry (ICP-MS), solid phase extraction (SPE) is a commonly used sample pretreatment technique to remove complex matrix, pre-concentrate target analytes and make the samples suitable for subsequent sample introduction and measurements. The sensitivity, selectivity/anti-interference ability, sample throughput and application potential of the methodology of SPE-ICP-MS are greatly dependent on SPE adsorbents. This article presents a general overview of the use of advanced functional materials (AFMs) in SPE for ICP-MS determination of trace elements and their species in the past decade. Herein the AFMs refer to the materials featuring with high adsorption capacity, good selectivity, fast adsorption/desorption dynamics and satisfying special requirements in real sample analysis, including nanometer-sized materials, porous materials, ion imprinting polymers, restricted access materials and magnetic materials. Carbon/silica/metal/metal oxide nanometer-sized adsorbents with high surface area and plenty of adsorption sites exhibit high adsorption capacity, and porous adsorbents would provide more adsorption sites and faster adsorption dynamics. The selectivity of the materials for target elements/species can be improved by using physical/chemical modification, ion imprinting and restricted accessed technique. Magnetic adsorbents in conventional batch operation offer unique magnetic response and high surface area-volume ratio which provide a very easy phase separation, greater extraction capacity and efficiency over conventional adsorbents, and chip-based magnetic SPE provides a versatile platform for special requirement (e.g. cell analysis). The performance of these adsorbents for the determination of trace elements and their species in different matrices by ICP-MS is discussed in detail, along with perspectives and possible challenges in the future development.