Enhanced electrochemically-directed oligonucleotide synthesis via porous silica thin-film for DNA data storage

A porous silica coating raised DNA synthesis yield more than 11-fold on an electrochemical chip for molecular data storage.

Image: Steppenwolf24 / Wikimedia Commons, CC BY-SA 4.0

Source: Microsystems & Nanoengineering, written by Shijia Yang; Dayin Wang; Qiaoli Liu; Xuedong Lan; Zequan Zhao; Weidong Wang; Kai Xia; Xiuli Gao; Yuan Luo; Jianlong Zhao (October 12, 2026). AI-generated summary by biochip.com, published . Not independently reviewed.

Key takeaways

  • Jianlong Zhao's team reported more than 1,821 pmol/cm² DNA yield, over 11 times higher than planar silica.
  • The porous silica microelectrode chip synthesized 121-nucleotide strands and recovered error-corrected encoded digital information.
  • The work does not establish performance at commercial DNA storage scale or in an independently validated system.

Researchers led by Jianlong Zhao developed a porous silica coating for a microelectrode-array chip that makes more DNA strands at each synthesis site. The platform is designed for DNA data storage, which encodes digital files into the sequence of DNA bases and later reads them back. By adding a sponge-like silica network to the chip, the team reported an oligonucleotide yield above 1,821 picomoles per square centimeter, more than 11 times that of a flat silica surface. The advance addresses a central problem for dense DNA-writing chips: shrinking each addressable site usually reduces the amount of DNA it can produce.

More surface area on a DNA-writing chip

Electrochemically directed synthesis, or EDS, builds DNA strands on selected locations of a microelectrode array. Each electrode generates acid locally, removing a protective chemical group so that the next DNA building block can attach only at the chosen site. It works a bit like turning on individual pixels in a display, except each activated pixel directs a chemical reaction.

EDS can be manufactured with semiconductor-style processes and can pack very large numbers of synthesis sites into a small area. But densely miniaturized electrodes offer little physical surface for DNA synthesis. That can leave too few copies of particular sequences, increasing the risk that some strands are lost or unevenly represented when stored data are recovered.

A sacrificial template creates accessible pores

The team covered titanium and platinum microelectrode arrays with a porous silica thin film. They made the film by spin-coating silica nanoparticles together with polystyrene microspheres, then heating the chip to remove the polymer spheres. What remains is an interconnected porous silica network with substantially more available surface than a smooth film.

The architecture aims to solve two competing needs at once. Its internal surfaces provide more locations where DNA can grow, while its connected pores allow synthesis reagents to move through the film. The researchers also optimized the conditions used to generate acid electrochemically, seeking to retain the sharp spatial control needed to activate neighboring chip sites independently.

Longer strands and digital information recovery

The porous-film platform supported parallel synthesis of oligonucleotides up to 121 nucleotides long. Oligonucleotides are short, custom-made DNA sequences, and their order of bases can represent the bits in a digital file. After synthesis, the team cleaved the DNA from the chip surface, quantified it, and sequenced products for analysis.

The researchers also encoded digital information into DNA sequences, wrote those sequences on the platform, and recovered the information using error correction. Their deletion, insertion, and substitution error statistics were comparable with other laboratory-built DNA data-writing systems. Deletions mean a base is missing, insertions add an extra base, and substitutions replace one base with another, all of which can alter stored information if not corrected.

Why This Matters

DNA is attractive for archival storage because it can theoretically pack enormous amounts of information into a small volume and remain stable for long periods under suitable conditions. Yet DNA storage depends on reliably making many distinct sequences, often in parallel. A high-density chip that produces too little DNA at each site may undermine those potential advantages.

By increasing usable synthesis area without abandoning electrode-level addressing, the porous silica approach offers a route around the density-yield trade-off in EDS. The next challenge is translating this chip-level demonstration into larger integrated molecular storage systems while maintaining synthesis accuracy, accessible pores, and reliable retrieval across much larger sequence libraries.

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