Apigenin/furfurylamine-based bio-polyamide derivative: Benzoxazine-isocyanide mechanochemistry preparation and application in Pb(II) electrochemical probing

Using renewable substances as the raw materials, and through relatively greener synthetic processes to implement the preparation of novel functional polymers is an idea that accords with the concept of “sustainable development” and is highly desirable in nowadays polymer science. In this study, apigenin (as renewable phenol) and furfurylamine (as renewable amine) were selected to prepare bio-based benzoxazine derivative (AP-f) through Mannich reaction . Using AP-f and diphenylmethane-based diisocyanide (IC) as reactants, a type of cross-linked, semi-aromatic polyamide derivative (Bio-PA) was successfully prepared via benzoxazine-isocyanide mechanochemistry (BIC-MC) by ball milling manner. Chemical structure , elemental composition , micro morphology and stacking state properties of Bio-PA were systematically characterized here. Multiple Pb(II)-affinitive molecular fragments (phenolic hydroxyl , tertiary amine and amide) were integrated into the structure of Bio-PA. Based on this, the application of Bio-PA as “enrichment-type” Pb(II) electrochemical probe was explored subsequently. The results showed that the introduction of Bio-PA significantly improved the response of Pb(II), and the modified electrode (Bio-PA/Nafion/GCE) illustrated satisfactory detection sensitivity and selectivity.