Researchers use electrochemistry to read data stored in molecules

Inspired by how DNA can pack massive quantities of information into tiny amounts of material, chemists have been working for years on ways to use molecules for data storage. They’ve investigated encoding information into DNA polymers, peptides, and even dots of dye.

Recent advances in sequence-defined polymerization have made it easier than ever to write messages into nonbiological molecules. But reading those messages typically relies on mass spectrometry, which is expensive to run and requires specialist know-how to interpret. That’s why researchers at the University of Texas at Austin worked out a way to use electrochemistry to extract information from molecular sequences (Chem 2025, DOI: 10.1016/j.chempr.2025.102571).

“It's much, much cheaper and can be done with a much smaller instrument,” says chemist Eric Anslyn, who led the work along with electrical engineer Praveen Pasupathy.

Building on their previous work on polyurethane-based data storage, the researchers created a series of four monomers, each bearing a ferrocene group with a distinct electrochemical signature. They then combined the monomers into oligomer chains of four monomers each.

Each of the 256 possible “four-letter words” can represent a different letter, number, or symbol, much like three-letter codons in nucleic acid sequences correspond to specific amino acids in protein instructions, Anslyn says.

To extract the data from the molecules, the researchers use a base to trigger the oligomers to fall apart one monomer at a time. They then use differential pulse voltammetry (DPV)—which employs voltage pulses to measure the electrochemical signatures of molecules—to determine which monomers are being released and in which order. By following how the signals change over time, the researchers can figure out the sequence.

Anslyn describes how, for a string made of monomers 1, 2, and 3 arranged into the sequence 3321, monomer 3 will be the first signal to appear in the DPV data readout. That signal will continue growing when the second monomer comes off. Eventually it will stop growing and the signal from monomer 2 will then appear, followed by a signal from monomer 1.

The researchers developed a computer model to analyze and interpret the electrochemistry data and match each sequence to its corresponding symbol. They demonstrated the technique by encoding an 11-character password written into 11 different molecules, decoding it, and using it to unlock a computer.

Hans Elemans, a chemist at Radboud University who researches polymer-based data storage but was not involved in the work, says Anslyn and Pasupathy’s electrochemical method is “a completely new approach” to decoding data from molecules. Although it still requires hands-on sample preparation and a couple of hours’ decoding time per molecule, it’s a solid advance toward more user-friendly sequencing, he says.

Pasupathy says the team is working on translating the approach to a chip-based, microfluidic system to streamline the analysis and reduce the hands-on chemistry—inching toward his and Anslyn’s ultimate dream of developing a way to get data-carrying molecules to “talk” directly to electronics.