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With the wide use of rare earth nanomaterials in industry, environmental control, and medicine with their unique properties, it has focused on the exposure of humans to the rare earth nanoparticles in recent years. Because of the similar properties of rare earth and calcium, rare earth nanoparticles can deposit in the bone and affect the osteogenic differentiation of bone mesenchymal stem cells (BMSCs). La(OH)3 nanoparticles are widely used in the catalysis, sensor, electrode, and luminescent materials. However, there are few reports about the bioactivity of La(OH)3 nanoparticles on the bone metabolism. In this work, three La(OH)3 nanorods have been got by hydrothermal method, Long-, Medium-, and Short-La(OH)3 nanorods, the lengths of which were of ~ 640, 255, and 80 nm, and the diameters of which were of ~ 85, 40, and 35 nm, respectively. All the La(OH)3 nanorods showed no effect on BMSCs viability and the blood compatibility. But the osteogenic differentiation showed a significant difference in La(OH)3 nanorods, in which Short-La(OH)3 nanorods showed the highest promoting effect on osteogenic differentiation. The potential mechanism in the osteogenic differentiation caused by three La(OH)3 nanorods was correlated with the different uptake efficiency in BMSCs and degradation in lysosome to form LaPO4. This work on La(OH)3 nanorods provides the basic data for the development of lanthanum-based nanoparticles. [ABSTRACT FROM AUTHOR]

Near infrared (NIR)-emitting persistent luminescent nanoparticles (PLNPs) have advantages such as long afterglow, high photostability and deep tissue spectral penetration. A NIR-emitting inner filter effect (IFE) probe for arsenic(III) is described here. It is composed of polyethyleneimine-coated PLNPs and gold nanorods (AuNPs) coated with dithiothreitol. The probe can detect arsenic(III) (= arsenite) selectively even in the presence of interfering substances. The PLNPs and AuNPs were prepared by a hydrothermal method combined with high-temperature calcination and seed-mediated growth mechanism, respectively. The PLNPs show excellent NIR luminescence (with excitation/emission peaks at 254/695 nm) and long afterglow (lifetime >1200 s). The use of polyethyleneimine improves water solubility and provides positive surface charges for the PLNPs. On exposure to arsenite ions, the luminescence of the probe at 695 nm is restored. Under the optimum conditions, the method can detect As(III) in the 0.067 to 13.4 μmol·L−1 concentration range with good linear relationship (R2 = 0.99734), and the detection limit (at S/N = 3) is 55 nmol·L−1. The precision of this method was demonstrated by 11 replicate detections of 2 μmol·L−1 As(III), and the relative standard deviations (RSD) is 2.1%. The practicality was evaluated by the analyses of real water samples and recoveries for the water samples spiked with 2, 5 and 10 μmol·L−1 of As(III) were 89.8%-100.1% with RSDs ranging from 3.0-5.7%.A near infrared-emitting inner filter effect (IFE) inhibition probe is presented. It is based on the combination of polyethyleneimine (PEI)-coated NIR-emitting persistent luminescent nanoparticles (type Zn1.25Ga1.5Ge0.25O4: Cr3+, ZGGO) (PLNPs-PEI) with dithiothreitol (DTT)-coated gold nanorods (AuNPs) (DTT-AuNPs) to detect arsenite. [ABSTRACT FROM AUTHOR]

A colorimetric probe for determination of As(III) ions in aqueous solutions on basis of localized surface plasmon resonance (LSPR) was synthesized. The dithiothreitol molecules with two end thiols covalently combined with Au Nanorods (AuNRs) with an aspect ratio of 2.9 by Au-S bond to form dithiothreitol coated Au Nanorods (DTT-AuNRs), acting as colorimetric probe for the determination of As(III) ions. With the adding of As(III) ions, the AuNRs will be aggregated and leading the longitudinal SPR absorption band of DTT-AuNRs decrease due to the As(III) ions can bind with three DTT molecules through an As-S linkage. The potential factors affect the response of DTT-AuNRs to As(III) ions including the concentration of DTT, pH values of DTT-AuNRs, reaction time and NaCl concentration were optimized. Under optimum assay conditions, the DTT-AuNRs colorimetric probe has high sensitivity towards As(III) ions with low detection limit of 38 nM by rules of 3σ/k and excellent linear range of 0.13–10.01 μM. The developed colorimetric probe shows high selectivity for As(III) ions sensing and has applied to determine of As(III) in environmental water samples with quantitative spike-recoveries range from 95.2% to 100.4% with low relative standard deviation of less than 4.4% (n = 3). [ABSTRACT FROM AUTHOR]

La(OH) 3 nanorods with different aspect ratios have been successfully synthesized by a simple hydrothermal method without using any surfactant, catalyst, or template. The amount of the alkali source in the initial solution and reaction time play a key role in controlling the morphology and particle size of the La(OH) 3 products. Subsequently, the as-obtained La(OH) 3 samples are used as precursor to fabricate the La 2 O 3 nanorods after an annealing process. The lanthanide ions Ln3+ (Ln = Er, Tb, Eu) doped La 2 O 3 samples exhibit characteristic emissions corresponding to the electronic transitions of the Ln3+ ions. Moreover, the morphologies and sizes of the luminescent materials have a great influence on their luminescence properties. Based on the unique luminescent properties and controllable morphology and size, these luminescent materials may find potential applications in fields such as lighting, optical displays, and optoelectronic devices. • La(OH) 3 nanorods with different aspect ratios were prepared by a hydrothermal method. • La(OH) 3 can be converted to La 2 O 3 nanorods after an annealing process. • The Ln3+ doped samples exhibit intense characteristic DC or UC multicolor emissions. • The morphologies and sizes have a great influence on the luminescence properties. • The luminescent materials may be potentially applied in lighting and displays. [ABSTRACT FROM AUTHOR]