by Prof. Ganesh D. Sockalingum, Université de Reims Champagne-Ardenne (URCA) / November 14, 2025
Every disease begins with quiet molecular changes: modifications in cell biochemistry and marker molecules circulating in our blood that happens long before tumors form or symptoms appear.
For decades, scientists have searched for a way to identify the earliest whispers of disease so as to intervene before it ever takes hold. One of the most powerful tools emerging from that quest is Fourier-Transform Infrared (FTIR) Spectroscopy, which uses invisible infrared light to read the chemical fingerprints that define every living system. It gives a unique insight into molecular information by analyzing the way molecules and chemical bonds vibrate. By capturing these spectral fingerprints, FTIR reveals the subtle molecular changes that mark the transition from health to disease states and offers a window into biology prior to the disease onset or imaging detects a tumor.
The Fingerprints of Life
Every molecule in our body, including proteins, lipids, sugars, nucleic acids, interacts with infrared light in its own distinctive way. As the light passes through, these molecules absorb specific wavelengths while their chemical bonds stretch, bend, and twist in rhythm. Together, these absorption patterns form a spectral fingerprint, revealing each molecule’s composition and the way its atoms move and resonate like instruments playing in a molecular orchestra.
By measuring these vibrations in a sample such as blood, saliva, urine, cell or tissue, FTIR captures an intricate snapshot of its entire biochemical landscape like a kind of molecular selfie of health or disease states.
In a healthy body, these patterns stay steady and balanced. But as cancer emerges, the body’s chemistry begins to change: metabolism rewires, proteins twist into new shapes, fats oxidize, and sugars build up; leaving behind a telltale molecular fingerprint. Every tiny biochemical change stemming from a disease state leaves its own trace in the infrared spectrum. When thousands of these spectra from healthy and diseased individuals are compared, powerful algorithms can learn to spot the hidden “signatures” of cancer. Sometimes long before any tumor can be seen on a scan.
From the Laboratory to the Clinic
Light can do more than illuminate. It can diagnose.
Using FTIR spectroscopy, we can tell healthy and cancerous tissues apart, define tumor margins during surgery, and even track how cells respond to therapy. We call these approaches spectral cytology and spectral histopathology, because they reveal the chemical snapshots of cells and tissues through light-matter interactions.
Perhaps most exciting is the rise of biofluid spectro-diagnostics, a single blood test becomes a window into the body’s chemistry. FTIR can detect subtle molecular changes that research has shown to correlate with cancers of the breast, prostate, liver, and beyond. Instead of chasing one biomarker at a time, it captures the body’s entire molecular landscape: a global biochemical signature that reflects health, imbalance, or disease in one sweeping view.
A New Frontier in Early Detection
Imagine detecting cancer not through an image of a mass, but through its subtle biochemical changes in a simple blood test that appear months or even years before a tumor forms.
That is the promise of vibrational spectroscopy.
By combining the sensitivity of optical measurements, novel hardware, and the power of machine learning, FTIR is helping medicine evolve from reactive treatment to proactive prevention. All this in a non-invasive and non-destructive manner.
Invisible to the eye, infrared light allows us to see the unseen and to detect the earliest, most delicate changes arising from disease onset. It reminds us that every living system carries its own quiet rhythm that, when carefully listened to, can reveal the first signs of disease and guide us toward a healthier future.
About the Author
Dr. Ganesh D. Sockalingum is a Professor of Biophotonics at the Université de Reims Champagne-Ardenne (France) and a leading figure in biomedical vibrational spectroscopy. With more than 140 scientific publications and over 11,000 citations, his work has advanced the use of FTIR and Raman spectroscopy for clinical diagnostics, spectral cytology, and biofluid analysis. Dr. Sockalingum has played key roles in major European biospectroscopy initiatives and is recognized for pioneering contributions that bridge physics, chemistry, and medicine to enable earlier, more accurate disease detection.
