Exploring current and future technologies to make sense of the biophoton phenomenon: a narrative review

Biophotons is the very weak light generated by cells. This light has been shown to change with different states of cell activity and/or cell health. Although their precise significance is still not clear, biophotons are thought to function as a means of cell-to-cell communication and cell repair. In this narrative review, we consider first, the current technology available that detects biophotons. These include (1) photomultipliers: these devices have advantages of giving real-time outputs, cover a relatively large detection area and have a low dark-noise per unit detection ability; their quantum efficiency is not great however and they do not have the ability to capture images; (2) image detectors: can capture images with an ultra-sensitive camera, together with count photons from living tissue; their process of acquiring an image can take a long time however, and their photon counts are less accurate than those obtained with photomultipliers and (3) histological methods: that relies on the reduction of silver (Ag)+ to Ag that is thought to mark sites of photon activation and can be identified with a light microscope; there are however, some issues on how this reduction process affects the tissue and whether it can influence biophoton count. Next, we consider prospects for future methods that may determine both the functional significance of biophotons, together with how their detection can be used clinically. The development of better technology in the field of biophoton research can reveal a better understanding of how the brain functions under both normal and pathological conditions.