Light talks: The role of biophoton in cellular communication.

Biophotons represent ultra-weak light emission (200-800 nm) spontaneously generated by living cells through oxidative metabolic processes, particularly within mitochondria. In 1923, Alexander Gurwitsch demonstrated non-chemical cellular communication in pioneering experiments on what he called 'mitogenetic radiation', which transmitted through quartz but not through glass: it was later confirmed to involve light and especially UV. Since then, this field has evolved to encompass sophisticated detection technologies and theoretical frameworks. Evidence suggests that biophotons, produced mainly by reactive oxygen species (ROS) and excited molecular intermediates during cellular respiration, may serve functional roles in intercellular signalling beyond being mere metabolic byproducts. In neural systems, biophotonic emissions correlate with brain activity, metabolic states, and oxidative stress levels, with emerging applications in neurodegenerative disease monitoring and cognitive assessment. Advanced detection methodologies using photomultiplier tubes (PMT) and electron-multiplying charge-coupled device (CCD) cameras have revealed species-specific spectral signatures and stress-responsive emission patterns. While quantum mechanical explanations remain debated, accumulating evidence supports biophotons as potential biomarkers for cellular health and novel communication pathways. Future therapeutic applications may integrate biophotonic monitoring with photobiomodulation (PBM) interventions for personalized medical treatments.