This paper focuses on the functionalization of double positively charged polyethylenimine (PEI)/Zr 4+ -polyamide (PA) nanofiltration (NF) membrane by connecting Zr 4+ with positively charged PEI-PA NF membrane surface. In particular, the properties of prepared PEI/Zr 4+ -PA NF membrane, performance on removing aquatic contaminants (Cr 3+ and trimethoprim), and its antifouling ability were evaluated in detail. In this regard, zirconium acetate was successfully adopted as the zirconium source for stable membrane surface charge control. Zr 4+ loading increased the hydrophilicity of the PEI-PA NF membrane, improved permeate flux, and enhanced the removal behavior of PEI/Zr 4+ -PA NF membrane especially when exposed to Cr 3+ and trimethoprim at high concentrations. Furthermore, effectiveness of PEI/Zr 4+ -PA NF membrane was not affected by high filtering degree, filtration cycle, and negatively charged macromolecules, such as bovine serum albumin (BSA). Also, antifouling ability of PEI/Zr 4+ -PA NF membrane could be further improved by continuously loading Zr 4+ .
Siqi Zhang,Amin Bao,Ting Sun,Erkang Wang,Jiahai Wang
By virtue of a biomimetic nanopore and single-walled carbon nanotubes, a new sensor for adenosine triphosphate (ATP) detection is designed. As compared to the routine approach, the present scenario does not entail the surface modification of nanopore with analyte-specific probes. The underlying mechanism relies on a symmetric nanopore sequentially modified with polyethyleneimine (PEI) and Zr 4+ that can quantitate the concentration of ATP-bound aptamer, while other free aptamers are removed by single-walled carbon nanotubes (SWNTs). The detection limit of the nanopore sensor is 27.46 nM, and the linear range is from 50 nM to 400 nM. The biosensor with an excellent selectivity against guanosine triphosphate (GTP), uridine triphosphate (UTP), and cytosine triphosphate (CTP) can be applied in the real samples such as Hela cell .
危险品化学品经营许可证（带存储）