An Electrochemical Sensor Based on Gold and Bismuth Bimetallic Nanoparticles Decorated L-Cysteine Functionalized Graphene Oxide Nanocomposites for Sensitive Detection of Iron Ions in Water Samples.

In this work, gold and bismuth bimetallic nanoparticles decorated L-cysteine functionalized graphene oxide nanocomposites (Au-BiNPs/SH-GO) were prepared and applied to selective detection of Fe(III) in lake and seawater samples by modifying onto glassy carbon electrodes. Bimetallic nanoparticles have various excellent properties and better catalytic properties because of the unique synergistic effect between metals. The modified electrode was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. Under optimized conditions, current peak intensity increased linearly with increasing Fe(III) concentration over the range of 0.2-50 µM and a detection limit of 0.07 µM (S/N = 3). The Au-BiNPs/SH-GO/GCE was used for the determination of Fe(III) in lake and seawater samples with recoveries ranged from 90 to 103%. Those satisfactory results revealed the potential application of the Au-BiNPs/SH-GO electrochemical sensor for heavy metals detection in environmental monitoring.

A 26-week 20(S)-ginsenoside Rg3 oral toxicity study in Beagle dogs.

20(s)-ginsenoside Rg3 is a red ginseng-derived compound with the formula C42H72O13 that has been increasingly used by humans, leading to safety concerns regarding this use. In the current study, we conducted a 26-week study during which 20(S)-ginsenoside Rg3 (0, 7, 20, or 60 mg/kg) was continuously administered orally to Beagle dogs in order to explore its toxicity in these animals, with control dogs receiving a vehicle capsule. In total, 10 dogs received each dose of this compound (n = 5 male, n = 5 female per dose). Animals were continuously monitored for a 26-week administration period and a subsequent 4-week follow-up recovery period. At the end of study, we observed no evidence of 20(S)-ginsenoside Rg3 toxicity in clinical indications, body weight, food intake, ophthalmoscopy, electrocardiogram, urinalysis, hematology, serum biochemistry, gross and histopathology findings. However, the kidney relative weight of animals receiving 60 mg/kg of compound was significantly elevated relative to control animals (5.15 ±â€¯0.88‰ vs. 4.11 ±â€¯0.59‰. P < 0.05), and this effect was reversed after 4-week recovery period. Based on these results, the NOAEL value for orally administered 20(S)-ginsenoside Rg3 in dogs is 20 mg/kg.

Preclinical safety of ginsenoside compound K: Acute, and 26-week oral toxicity studies in mice and rats.

Ginsenoside compound K (CK) is a hydrolysate of ginsenosides in the soil bacteria. This study evaluated the toxicity of CK as acute and the 26-week repeated-dose. The results of acute toxicity show that CK administered orally to rats and mice did not cause mortality or toxicity at the maximum dosage of 8 g/kg and 10 g/kg, respectively. In the toxicity study for 26-week, rats were administered with CK at doses of 13, 40, or 120 mg/kg, and were observed for 26 weeks and recovery periods of four weeks. Under the conditions, asthenia, hypoactivity, loss of fur and body weight reduction were transiently noticed in males of 120 mg/kg group. Hepatotoxicity and nephrotoxicity also were evident including the elevation of liver and kidney relative weight, along with focal liver necrosis as well as the increase in plasma enzymes (ALT and ALP) in male rats receiving CK (120 mg/kg), but this toxicity might be reversible. For 13 and 40 mg/kg CK groups, there was no significant variation in food habits, clinical signs, urine analysis, body weight, biochemical and hematological values, organ coefficient and histopathology examination. The NOAEL for male and female rats were observed to be 40 and 120 mg/kg, respectively.

Environmental separation and enrichment of gold and palladium ions by amino-modified three-dimensional graphene.

The excellent adsorption properties of three-dimensional graphene (3DG) can be further enhanced by triethylenetetramine modification to increase its adsorption capacity for precious metal ions. Herein, we successfully synthesized an amino-modified 3DG (N-3DG) adsorbent with improved adsorption conditions with regards to pH value, dosage, and adsorption time. Adsorption equilibrium was reached at pH 3 over 120 min. In addition, the theoretical basis for the adsorption of N-3DG is provided by fitting the adsorption isotherm model. The synthesized material was tested in seawater and lake water samples for the adsorption of precious metals, namely Au(iii) and Pd(ii), achieving a recovery rate of 87% to 106% as assessed by inductively coupled plasma mass spectrometry. Thus, N-3DG showed good adsorptivity. The present results indicate that N-3DG materials could have a viable application in environmental and sewage treatment in the near future.

[Determination of 16 elements in the different pine pollen by TXRF].

After microwave digestion, 16 elements in pine pollen were simultaneously determined by TXRF. The results show that all the 16 elements were found in all pine pollens. There was a significant difference in the average content of the element such as Ca, Ti, Mn, Zn and Rb between different groups of pine pollen (P < or = 0.01). There was a difference in the average content of the element such as K, V, Fe, Co, Cu and Sr between them (P < or = 0.05). And there was no difference in the average content of the element such as Cr, Ni, As, Pb and Se between them. The results also show that pine pollen has the spectral characteristics of warm property or cold property drug. They were closely related to the tree species and the growth environment or the growth area.

[Study on the interaction of methyl pheophorbide-a and bovine serum albumins by fluorescence].

The binding reaction of methyl pheophorbide-a with bovine serum albumins (BSA) in aqueous solution was studied by fluorescence and UV-Vis absorption spectra. The results indicated that the combination reaction of them was a single static quenching process. In aqueous solution, methyl pheophorbide-a strongly bound BSA with the apparent molar ratio of 2 : 1 because of methyl pheophorbide-a polymerized by itself. The binding constant KB was 6.7 x 10(4) L x mol(-1). In mixture solvent of tetrahydrofuran and water, methyl pheophorbide-a existed as single molecule and bound BSA with a molar ratio of 1: 1. There is single position for combining methyl pheophorbide-a with BSA. The shortest binding distance (r = 3.50 nm) and energy transfer efficiencies (E = 0.39) between donor (BSA) and acceptor (methyl pheophorbide-a) were obtained by Förster's nonradiative energy transfer mechanism.