Electrochemical sequencing of sequence-defined ferrocene-containing oligourethanes

The growing demand for data storage has driven research into alternative storage media. Although DNA has proven effective, synthetic sequence-defined polymers (SDPs) offer tailored information-encoding potential. Despite advances in SDP chemodiversity, sequencing methods remain limited, primarily relying on tandem mass spectrometry. To address this, we developed an electrochemical sequencing technique for sequence-defined oligourethanes (SDOs), incorporating four ferrocene-based monomers. Our method combines controlled chain-end degradation with differential pulse voltammetry (DPV) to yield unique voltammograms specific to each sequence. Coupled with kinetic modeling and principal component analysis (PCA), this approach enables accurate sequence identification. We automated this process with a Python program that decodes sequences by comparing experimental DPV data to predicted profiles and thereby successfully demonstrated the encoding and decoding of an 11-character password. The technique expands the toolbox for sequencing SDPs and opens new possibilities for molecular data storage.