Fluorescence enhancement method for palmatine extraction by SWMONTs.

Single-walled metal-organic nanotubes (SWMONTs) could be dried in vacuum to obtain SWMONTs with activation sites. Glycine and diethylenetriamine (2,3-NH2) were added to activated SWMONTs, and SWMONTs-COOH and SWMONTs-NH2 nanoparticles could be obtained. SWMONTs-NH2 nanoparticles could be covalently modified by single-ended and double-ended carboxyl polyethylene glycol (PEG-CM, CM-PEG-CM), and SWMONTs-PEG and SWMONTs-PEG-COOH nanoparticles could be obtained. The structure of SWMONTs-NH2, SWMONTs-COOH, SWMONTs-PEG and SWMONTs-PEG-COOH nanoparticles could be determined by XPS (X-ray photoelectron spectroscopy). The results showed that the amidation reactions were successful. Palmatine (Pal) extraction experiments exhibited that, as for SWMONTs-COOH, SWMONTs-PEG and SWMONTs-PEG-COOH nanoparticles, the best adsorption could be obtained at pH 8, pH 10 and pH 12, which showed that palmatine has a better adsorption effect in an alkaline environment. [ABSTRACT FROM AUTHOR]