Singapore researchers have developed the first optical nanosensor capable of detecting indole-3-propionic acid (IPA), a gut health biomarker, in minutes—a breakthrough that could transform how people monitor their digestive health without expensive lab equipment.
IPA is a metabolite produced by gut bacteria when they break down dietary tryptophan, an amino acid essential for protein synthesis. This molecule plays a crucial role in regulating inflammation and oxidative stress, and scientists have linked abnormal IPA levels to inflammatory bowel disease, type 2 diabetes, and liver disease. Until now, detecting IPA required costly mass spectrometry tests that are impractical for routine screening or point-of-care diagnostics. That gap has frustrated clinicians and researchers eager to offer patients faster, more accessible monitoring of their gut health status.
The collaborative team behind the breakthrough includes researchers from the National Institute of Education and Nanyang Technological University (NIE NTU), Singapore-MIT Alliance for Research and Technology (SMART), and clinicians from the National University Hospital and Yong Loo Lin School of Medicine at the National University of Singapore. Their work, published in Advanced Healthcare Materials, describes a fluorescence-based platform that delivers results in minutes while demonstrating high selectivity—meaning it can distinguish IPA from closely related metabolites commonly found in the gut, enabling accurate detection even in complex biological environments like blood serum.
"This is the first time we are able to directly and rapidly measure IPA levels in biological samples using an optical nanosensor," said Assistant Professor Mervin Ang from NIE, a co-first author of the research. The innovation builds on technology originally developed by SMART's Disruptive & Sustainable Technologies for Agricultural Precision (DiSTAP) research group to monitor plant health signals and stress responses. By redesigning the nano- and optical-sensing platform, the team successfully adapted the agricultural technology for human health applications.
What makes this nanosensor particularly promising is its dual-mode capability. The technology operates in both a visible fluorescence mode for rapid, low-cost, high-throughput screening of biological samples, and a near-infrared mode with wavelengths that penetrate deeper into tissues. The near-infrared capability opens a door to future in vivo applications and integration into wearable devices, potentially enabling patients to perform home-based testing or receive continuous monitoring of their gut health status.
For people living with chronic conditions like inflammatory bowel disease, this could mean the difference between detecting disease flare-ups early and managing their health with greater autonomy. Rather than waiting days for lab results or making costly clinical visits, patients might eventually monitor their IPA levels at home and adjust their care proactively.
"By focusing our molecular recognition on this important gut health biomarker, we've demonstrated a powerful new tool that could one day enable proactive, personalized health care," said Professor Michael Strano from MIT, the corresponding author and SMART DiSTAP Lead Principal Investigator. The team's work represents a meaningful step toward making gut health monitoring as routine and accessible as checking blood pressure—turning what was once the domain of specialized laboratories into a tool available anywhere, anytime.