Iso‐E‐Codelock: A Rebuilding‐free Electrochemical Chip with a Customizable Decoding Probe for Real‐Time and Portable Pathogen Diagnostics

Abstract In order to realize portable pathogen diagnostics with easier quantitation, digitization and integration, we develop a ready‐to‐use electrochemical sensing strategy (Iso‐E‐Codelock) for real‐time detection of isothermal nucleic acid amplification. Bridged by a branched DNA as codelock, the isothermal amplicon is transduced into increased current of an electrochemical probe, holding multiple advantages of high sensitivity, high selectivity, signal‐on response, “zero” background and one‐pot operation. Through a self‐designed portable instrument (BioAlex PHE−T), the detection can be implemented on a multichannel microchip and output real‐time amplification curves just like an expensive commercial PCR machine. The microchip is a rebuilding‐free and disposable component. The branch codelock probe can be customized for different targets and designs. Such high performance and flexibility have been demonstrated utilizing four virus (SARS‐CoV‐2, African swine fever, FluA and FluB) genes as targets, and two branch (3‐way and 4‐way) DNAs as codelock probes.