Gel-based electrochemical DNA synthesis for quasi-solid-state data storage

Chemically synthesized DNA has been considered a promising medium for data storage. Among various methods, electrochemical synthesis is simple and easy to miniaturize, attracting much attention. However, conventional DNA synthesis uses phosphoramidite chemistry involving multi-step liquid-phase reactions and complicated liquid manipulation, restricting scalability and practical application. Here, we report the quasi-solid-state electrochemical DNA synthesis based on gels. All reagents required for different synthesis steps are contained in separate gels without mixing or dilution. Instead of complicated liquid manipulation, DNA synthesis on the electrode requires only relative motion between the electrode and gels. Similarly, blank gels with only acetonitrile are reused to clean the electrode surface without washing with plenty of liquid. We demonstrate our method is scalable using an electrode array for parallel DNA synthesis.