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.