NTU Singapore and SMART scientists develop sensor that could help track gut health
New nano-sized sensor can detect the biomarker within minutes, tested on 125 human plasma samples
Scientists from the National Institute of Education, Nanyang Technological University, Singapore (NIE, NTU Singapore) and the Singapore-MIT Alliance for Research and Technology (SMART) have developed a nanosensor that can quickly detect a gut health biomarker linked to inflammation and disease.
The sensor detects indole-3-propionic acid, known as IPA, a molecule produced by gut bacteria when they break down tryptophan, an amino acid found in food. IPA has been linked to gut health and diseases such as inflammatory bowel disease, type 2 diabetes and liver disease.
Today, IPA is usually measured using specialised laboratory equipment, such as mass spectrometry which is costly and time-consuming, making it less suitable for routine checks or rapid testing.
The new sensor gives a fluorescent signal when IPA is present – meaning it lights up when IPA is detected. This allows researchers to measure IPA levels within 30 minutes.
This research, published recently in Advanced Healthcare Materials, was done with clinicians from the National University Hospital (NUH) and the Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine).
Assistant Professor Mervin Ang from NIE, NTU Singapore, co-first author of the study, said: “This is the first time we can directly and rapidly measure IPA levels in biological samples using an optical nanosensor. This novel approach, which moves away from traditional mass spectrometry, can pave the way towards faster and more accessible ways of monitoring gut health in real-world settings.”
Tested on patient samples
To test the sensor, the research team worked with NUH clinicians to study 125 human plasma samples from healthy individuals and patients with gastrointestinal diseases.
The team found clear differences in IPA levels between healthy individuals and patients with inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis.
Patients with active gut inflammation had lower IPA levels. This is in line with earlier clinical findings that suggest IPA is linked to gut inflammation.
Adjunct Associate Professor Jonathan Lee, Senior Consultant, Division of Gastroenterology and Hepatology, Department of Medicine, NUH and NUS Medicine, and co-first author of the study, said: “From a clinical perspective, having a rapid and minimally complex way to assess metabolite levels like IPA could be very valuable. It has the potential to complement existing diagnostic tools and provide additional insights into patients with inflammatory bowel diseases.”
The sensor was also tested with serum and plasma, the liquid parts of blood commonly used in medical testing. This is an important step towards further validation for clinical use.
Adapted from plant health research
The technology builds on earlier sensor work by SMART’s Disruptive & Sustainable Technologies for Agricultural Precision interdisciplinary research group, known as DiSTAP.
The original platform was developed to monitor plant health, including signals related to plant growth and stress. For this study, the team adapted the platform to detect IPA for human health research.
Professor Michael Strano, SMART DiSTAP Lead Principal Investigator, Carbon P. Dubbs Professor of Chemical Engineering at MIT, and corresponding author of the study, said: “This work builds on technology at SMART DiSTAP on molecular recognition. We have used techniques like this to measure hormones and metabolites in living plants for agriculture, and have now applied it to the human gastrointestinal system.
“We were able to apply it to this long-standing challenge in gut health. By focusing our molecular recognition on this important gut health biomarker, we’ve demonstrated a powerful new tool that could one day enable proactive, personalised healthcare. The tool promises near-instant insights into gut wellness or the status of chronic diseases like IBD.”
Beyond research on gut disease, the sensor could help scientists study how diet, probiotics and potential therapeutics affect IPA levels.
The research team has since received an Innovation to Startup (I2Start) Innovation Grant – a joint programme by the SMART Innovation Centre, the National Health Innovation Centre Singapore (NHIC), and Enterprise Singapore (ESG) – to further validate and develop the technology. The team aims to explore how the sensor could be translated into a future point-of-care tool for gut health monitoring.
Future work will focus on expanding the platform to detect more gut-related metabolites and improving how signals are analysed. The researchers will also study whether the technology can be integrated into portable platforms for easier testing outside specialised laboratories.
The research was supported by the Intra-CREATE Seed Collaboration Grant. Research conducted at SMART was supported by the National Research Foundation, Singapore (NRF) under its Campus for Research Excellence and Technological Enterprise (CREATE) programme.
Notes to Editors
The paper titled “Fluorescent Nanosensor for Indole-3-Propionic Acid Detection in Gut Health Monitoring” was first published online in Advanced Healthcare Materials on 2 May 2026. DOI: 10.1002/adhm.202503434.
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