Microwell-arrayed chip with confined self-assembly of silica nanoparticles for high-capacity DNA synthesis

Chip-based de novo DNA synthesis technology is crucial for advancing synthetic biology. However, the limited capacity of microchip-based synthesis hinders its direct application, as large quantity of oligonucleotides (oligos) are often required. This paper proposed a high-capacity DNA synthesis chip that utilizes silica nanoparticles (Si-NPs) self-assembled on the inner surface of confined microwells through a vertical deposition technique. Effects of Si-NPs mass fraction, size, and solvent type on the self-assembly (SA) process within each microwell were thoroughly evaluated. Oligos were successfully synthesized on the Si-NPs-assembled chip and validated via hybridization with fluorescent-labeled probes. A three-fold increase in synthesis capacity was estimated on a single layer of Si-NPs, and the number of SA layers can be easily adjusted by altering the composite of the Si-NPs suspension. The proposed microarrayed chip resolves the trade-off between synthesis throughput and capacity and offers significant potential for the next generation of ultrahigh-throughput DNA synthesis in synthetic biology.