Digital DNA Nanostructures for Ultrasensitive Multiplexed Heavy Metal Sensing via Nanopore Platforms

ABSTRACT Heavy metal contamination in freshwater ecosystems represents a persistent global health crisis, yet scalable monitoring is hindered by the trade‐off between sensitivity and multiplexing capability in current sensors. Here, we overcome this limitation by developing a single‐molecule nanopore platform that integrates digitally encoded DNAzyme probes for simultaneous, ultrasensitive quantification of diverse metal ions. Our design features programmable DNAzyme probes that translate specific chemical recognition into distinct digital current fluctuations readable by a nanopore. This architecture simultaneously discriminates six critical metal ions (Pb 2+ , Hg 2+ , UO 2 2+ , Ca 2+ , Mn 2+ , Zn 2+ ) with picomolar sensitivity (1 p m for Pb 2+ ). We demonstrated the platform's robustness by profiling metal contaminants in natural lake water and soil matrices within 1 h, achieving accuracy comparable to inductively coupled plasma mass spectrometry (ICP‐MS). By digitalizing chemical recognition, this library‐based approach provides a versatile and practically relevant platform for environmental surveillance, with strong potential toward future field‐deployable and decentralized water safety monitoring applications.