A fungal-modified material with high uranium (VI) adsorption capacity and strong anti-interference ability.

With open-chain polyether as the bridge chain, a new fungal-modified material with diamidoxime groups was prepared by a series of uncomplex synthesis reaction. The orthogonal experiment obtained its optimized adsorption conditions as follows: the initial pH value of 6.5, the initial uranyl concentration of 40 mg L-1, the contact time of 130 min, and the a solid-liquid ratio of 25 mg L-1. The maximum adsorption capacity of target material was 446.20 mg g-1, and it was much greater than that of the similar monoamidoxime material (295.48 mg g-1). The linear Langmuir (R2 = 0.9856) isotherm models and the linear pseudo-second-order kinetic model (R2 = 0.9931) fit the experimental data of uranium (VI) adsorption better, indicating the adsorption mechanism should mainly be the monolayer adsorption and chemical process. In addition, the relevant experiments exhibited the prepared material had the good reusability, which reached 84.25% of the maximum capacity after five cycles, and the excellent anti-interference performance. The above features suggest the modified fungus material will have the good application prospect in the future.

Fluorescent nitrogen-doped carbon dots for high selective detecting p-nitrophenol through FRET mechanism.

A facile, friendly and one-step hydrothermal protocol was used to synthesize nitrogen-doped carbon dots (N-CDs) by utilizing hexamethylenetetramine and ethanediamine as the carbon and nitrogen sources. It demonstrated good water solubility and fluorescence properties were stable, whether in acidic or alkaline. Quantum yield (QY) of N-CDs was 8.3% at an excitation wavelength of 325 nm with maximum emission at 425 nm. The fluorescence of N-CDs achieved very high fluorescence quenching of 60% in the detection of p-nitrophenol (p-NP) in aqueous medium via fluorescence resonance energy transfer (FRET) mechanisms. Under optimum conditions, fluorescence probs of N-CDs had strong selectivity to p-NP, and the fluorescence intensity was linearly proportional to p-NP concentration from 0.5 to 70.0 µM with a detection limit of 0.201 µM. The corresponding cell experiments were also performed, indicating that the prepared N-CDs possessed low cytotoxicity and good biocompatibility. Meanwhile, the N-CDs can be used for the determination of p-NP in river water and industrial wastewater.