Ammonia solution nh3 h2o

Polyallylamine hydrochloride (PAH, weight-average molecular weight 150 000) was supplied by Nitto Boseki Co., Ltd. (Tokyo, Japan). l-Ascorbic acid (l-AA) and ammonia solution (NH₃·H₂O) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Methotrexate (MTX) was purchased from Huzhou Prospect Pharmaceutical Co. (Zhejiang, CN). Dialysis membrane (molecular weight cut-off = 8000–14 000 Da) was purchased from Shanghai Green Bird Technology development Co., Ltd. Human lung adenocarcinoma cells (A549) were purchased from Shanghai Cell bank (Shanghai, CN). All reagents were of analytical grade and used without further purification. All the aqueous solutions were prepared using Milli-Q water with a resistivity of 18.2 MΩ (Purelab Classic Corp., USA).

All chemical agents were commercially available. They were used without further purification. The reactant 4-CBA were obtained from Aladdin Chemical Reagent (Shanghai, China). Palladium chloride was purchased from Sigma-Aldrich. Activated carbon was provided by Sinopec Shanghai Petrochemical Company Limited. Zinc nitrate hexahydrate, 2-methylimidazole, phosphoric acid (H₃PO₄, 85 wt% in H₂O), ammonia solution (NH₃ ▪ H₂O, 25 wt% in H₂O) were purchased from Sinopharm Chemical Reagent Co., Ltd.