Microreactor Array Based On Three-Phase Contact Line Controlling and Sintering For De Novo Oligonucleotide Synthesis

This paper presents a low-cost and high-efficiency packed microreactor array with enhanced reaction surface area for high-capacity de novo oligonucleotide synthesis on-chip. Silicon wafer was pre-treated with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFOS) to obtain a hydrophobic surface, thus a higher receding contact angle. By inkjet printing, SiO
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nanoparticles droplets array were printed on the hydrophobic surface. Driven by the controlled sliding of three-phase contact line (TCL) during solvent evaporation, nanoparticles were closely aggregated to form a densely packed dots array, and the higher receding contact angle, the higher height-to-diameter ratio of dots would be achieved. After sintering, nanoparticles can be physically bonded and thus inherently keep the array configuration after hundreds of cycles of solvent treatment, which provides a favorable support for oligonucleotide synthesis. Experiments have validated that the PFOS-based microreactor array can achieve higher and more uniform fluorescence intensity, indicating that a higher density of oligonucleotide has been synthesized on the posts.