In Situ Growth of Ultrasmall Nanochannels in Porous Anodized Aluminum Membrane and Applied in Detection of Lead Ion.

The transport of ions in nanochannels has received considerable interest owing to the unique transport properties and potential applications. In this study, ultrasmall nanochannels (0.8-1.2 nm) were fabricated in porous anodized aluminum (PAA) membrane in situ growth. 2-Methylimidazole and zinc nitrate were used as the reaction precursor solkution, and then zeolitic imidazolate framework (ZIF-8) nanoparticles were sufficiently filled in PAA nanochannels to form a ZIF-8/PAA nanochannels composite membrane. Because ZIF-8 is a microporous material and has a strong ability to adsorb heavy metals, the composite membrane was used as a biosensor to detect lead ion (Pb2+) by the coordination interaction between Pb2+ and nitrogen atoms. The detection limit reached to 0.03 nM due to the enrichment of nanochannels under electric field. The sensor has a good linear range for Pb2+ from 10 nM to 10 μM.