A DNA Data Storage System Using Electrochemically Active Non-natural Oligonucleotides with Flexible Microfluidic Chips

Introducing non-natural oligonucleotides can provide DNA as a data storage medium with higher storage density and novel data storage paradigms. In particular, electrochemically active non-natural oligonucleotides can be detected through electrochemical signals, allowing data storage to retrieve data. Here, we present a DNA-based electrochemical readout data storage system capable of identifying different non-natural, electroactive bases (methylene blue- and ferrocene-modified bases) for DNA. The system utilizes a flexible electrochemical microfluidic chip, where data writing is achieved through DNA hybridization, and the parallel electrochemical signal acquisition enables data reading. Using methylene blue- and ferrocene-modified oligonucleotides as a demonstration, which allows 4 (2²) combinations on an electrode for the data storage, we successfully encoded and retrieved a 120-bit text file based on quaternary coding on a flexible electrochemical microfluidic chip. Our system may offer potential applications for electrochemical readout from DNA data storage system.