When zebrafish larvae glowed less in a University of Bath lab, scientists knew they were seeing diabetes in action. The dimmer light wasn’t a malfunction—it was a signal. Tiny fluorescent probes, designed to detect glucose, had revealed higher sugar levels in insulin-deficient fish, offering researchers a real-time window into metabolic disease inside a living body. This breakthrough could change how we study not only diabetes but also cancer and other conditions tied to sugar metabolism.
Glucose is essential for life, fueling our cells with energy. But tracking it inside living tissues has long been a scientific hurdle. Standard tools often fail to capture rapid changes or require invasive methods. Now, a team led by Professor Sofia I. Pascu, Dr. David Gurevich, and Professor Tony D. James has created glowing molecular sensors that bind to sugars and report back through light. These probes use boronic acids—chemicals that latch onto glucose—and pair them with a high-precision imaging method called multiphoton fluorescence lifetime imaging microscopy (MP-FLIM). Instead of just measuring brightness, MP-FLIM tracks how long the glow lasts, allowing scientists to map exactly where and when cells take up sugar.
The team tested their probes on zebrafish larvae, a common model for human disease. After exposing the fish to glucose, they saw clear changes in fluorescence within the digestive system. More importantly, they could tell apart diabetic-like fish from healthy ones—those with the mutation showed significantly reduced signals due to their elevated glucose levels. In cultured cells and live animals alike, the sensors worked in real time, opening doors to observing disease as it unfolds.
This isn’t just about watching sugar move. Because many cancers also alter glucose metabolism, these probes could help identify tumors early or test new drugs more effectively. The platform might one day be adapted to track other key carbohydrates, supporting personalized medicine and faster diagnosis. The project was a global effort, uniting chemists, biologists, and physicists from the University of Bath, University of Birmingham, Universidad Autónoma de Madrid, CSIC, and STFC Rutherford Appleton Laboratory. It also honors the late Professor John S. Fossey, a pioneer in boronic acid chemistry whose work helped lay the foundation.
"Our work demonstrates that synthetic carbohydrate-recognizing probes can monitor glucose-related processes in living organisms in real time," says Professor Pascu. As research continues, these glowing sensors may soon become vital tools in the fight against some of the world’s most widespread diseases.