Amount Of Cd Ions Research Articles

Enhancement and broadening of near infrared photoluminescence in Ag2X (X= S, Se) quantum dots via Cd doping for mini light-emitting diodes towads non-invasive bioimaging

Exploring excellent near infrared-II (NIR-II) emitting materials is desirable for the advancement of high quality bioimaging, in virtue of the lower scattering, deep penetration and high sensitive of biological components in the second optical transmission window. Colloidal Ag2X (X = S, Se) nanocrystals exhibit tunable NIR photoluminescence in the second NIR region. However, the lack of highly efficient broadband NIR emitting Ag2X (X = S, Se) nanocrystals limits their spectroscopy applications. Herein, cadmium (Cd) doped Ag2X (X = S, Se) nanocrystals were prepared through a facile hydrothermal method at room temperature. The NIR luminescence was efficiently enhanced through controllable doping a little amount of Cd ions into the Ag2X (X = S, Se) quantum dots (QDs). Simultaneously, the great broadening of NIR emission was achieved in the Cd doped Ag2Se QDs, and the maximum full width at half maximum could reach up to 530 nm. Following the general principles of photoluminescence light-emitting diode (LED) devices, the fabricated NIR mini LEDs) light sources based on Cd doped Ag2Se QDs exhibited broadband NIR electroluminescence and superior optoelectronic stability, and were successfully employed for clear vessel imaging. The works proves the feasibility of NIR mini LEDs in non-invasive bioimaging, and paves way for the miniaturized broadband NIR light sources.

Nitric oxide amplifies cadmium binding in root cell wall of a high cadmium-accumulating rice (Oryza sativa L.) line by promoting hemicellulose synthesis and pectin demethylesterification

Nitric oxide (NO) is tightly associated with plant response against cadmium (Cd) stress in rice since NO impacts Cd accumulation via modulating cell wall components. In the present study, we investigated that whether and how NO regulates Cd accumulation in root in two rice lines with different Cd accumulation ability. The variation of polysaccharides in root cell wall (RCW) of a high Cd-accumulating rice line Lu527–8 and a normal rice line Lu527–4 in response to Cd stress when exogenous NO supplied by sodium nitroprusside (SNP, a NO donor) was studied. Appreciable amounts of Cd distributed in RCW, in which most Cd ions were bound to pectin for the two rice lines when exposed to Cd. Exogenous NO upregulated the expression of OsPME11 and OsPME12 that were involved in pectin demethylesterification, resulting in more low methyl-esterified pectin and therefore stronger pectin-Cd binding. Exogenous NO also enhanced the concentration of hemicellulose and the amount of Cd ions in it. These results demonstrate that NO-induced more Cd binding in RCW in the two rice lines through promoting pectin demethylesterification and increasing hemicellulose accumulation. Higher OsPMEs expression and more hemicellulose synthesis contributed to more Cd immobilization in RCW of the high Cd-accumulating rice line Lu527–8. The main findings of this study reveal the regulation of NO on cell wall polysaccharides modification under Cd stress and help to elucidate the physiological and molecular mechanism of NO participating in Cd responses of rice.

Synthesis and identification of meta-(4-bromobenzyloxy) benzaldehyde thiosemicarbazone (MBBOTSC) as novel ligand for cadmium extraction by ultrasound assisted-dispersive-ionic liquid-liquid micro extraction method

In this research, meta-(4-bromobenzyloxy) benzaldehyde thiosemicarbazone (MBBOTSC) as a novel ligand was synthesized from the reaction between meta-(4-bromobenzyloxy) benzaldehyde and thiosemicarbazide under basic condition in water and ethanol as solvents. Ligand has the ability to chelate ions and therefore, it was used to form a complex and extract ions. Then, the cadmium ions in water and wastewater samples were separated based on MBBOTSC by ultrasound assisted-dispersive-ionic liquid-liquid microextraction method (USA-D-ILLME) before determination by AT-F-AAS. The MBBOTSC ligand was added to the mixture of the ionic liquid/acetone (IL/AC, [OMIM][PF6]) and then injected by syringe to 50 mL of water samples at pH 6-7. The sample was put into the ultrasonic accessory for 5 minutes, after complexation (Ligand-Cd; RS…Cd….RS), the water sample was centrifuged for 3 min for phase separation. Due to complexation and back-extraction of Cd in liquid phase, the amount of Cd ions in the water samples was determined by AT-F-AAS . In optimized conditions, the Linear ranges and LOD for 50 mL of water samples were obtained 1-36 μg L-1 and 0.3 μg L-1, respectively (Mean RSD= 1.26%). The validation results were successfully achieved by spiking real samples and using ET-AAS.