A carbon nanotube sensor from MIT and Singapore reads a gut bacteria molecule tied to inflammatory bowel disease in minutes from a blood sample, validated in a 125 patient study.
The gut manufactures a small molecule that helps police inflammation. That molecule, indole-3-propionic acid or IPA, is a byproduct of gut bacteria breaking down the amino acid tryptophan, and it circulates through the bloodstream influencing oxidative stress and immune signaling. Researchers have spent the past decade linking low IPA levels to inflammatory bowel disease, Type 2 diabetes, and liver disease, and more recent peer-reviewed work has tied the molecule to diabetic retinopathy, postoperative delirium, cardiotoxicity, and influenza resistance.
The catch is that the only reliable way to measure IPA today is mass spectrometry, a room-sized instrument that costs north of $200,000 and lives in specialized labs. The result takes hours, and the price per sample is high enough to keep the test out of routine checkups. A team at MIT and Singapore's National Institute of Education wants to change that equation with a much smaller tool: a fluorescent sensor built around a carbon nanotube that lights up in the presence of IPA and produces a readout in minutes from a serum or plasma sample, no mass spectrometer required.
The platform, reported by MIT News on June 15, 2026, was built by Michael Strano's group at MIT, the Carbon P. Dubbs Professor of Chemical Engineering, in collaboration with the Singapore-MIT Alliance for Research and Technology's Disruptive and Sustainable Technologies for Agricultural Precision research group, known as SMART DiSTAP. The chemistry was originally developed to monitor plant health, and adapting it to a human biomarker required new selectivity work: the team had to teach the carbon nanotube to ignore structurally similar tryptophan metabolites while still responding to IPA. The sensor produces two optical signals, a visible fluorescence band useful for high-throughput screening and a near-infrared band that penetrates tissue, which is what makes a wearable or implantable version conceivable on the same chemistry.
In a 125-patient clinical study run with clinicians at Singapore's National University Hospital, the sensor reproduced a pattern that mass spectrometry had already documented: patients with active inflammatory bowel disease, including Crohn's disease and ulcerative colitis, showed lower circulating IPA than healthy controls. The co-first authors are Mervin Ang, formerly SMART DiSTAP's associate scientific director and now at Singapore's National Institute of Education, and Jonathan Lee, a gastroenterologist at NUH and adjunct at the NUS Yong Loo Lin School of Medicine. The peer-reviewed paper in Advanced Healthcare Materials is open access.
That validation matters, but the work is research-stage, not an approved diagnostic. The published platform has been demonstrated on in-vitro plasma and serum samples; any version that sits on a patient's skin or ships to a home medicine cabinet remains a roadmap, not a product. Sensitivity and selectivity against mass spectrometry will need fuller benchmarking, and the test has not been cleared by regulators. The team's longer-term ambitions include clinic-side screening for gut inflammation, home-based or wearable continuous monitoring of IBD flare-ups, and rapid functional readouts for probiotic and dietary intervention trials, but those use cases are years out and have not yet been demonstrated in humans.
What to watch next: whether the same carbon-nanotube chemistry can be re-engineered into a stable wearable or point-of-care cartridge, and whether larger, multi-site clinical studies confirm the IPA-depression signal in IBD cohorts at a sensitivity that competes with mass spectrometry. The biology that makes IPA interesting is already on solid ground. The open question is whether the new sensor can carry that biology from a research lab into a routine blood draw.