Quantum biology and ultraweak photon emission: an overlooked intersection?

Biophotons–or ultraweak photon emissions (UPE) – remain a peripheral research subject compared to conventional topics in quantum biology such as photosynthesis, avian magnetoreception, and olfaction, despite significant intersections between the fields. Re-examining UPE research through the lens of quantum biology may help address confounding questions around these light-matter interactions. One principal argument against a biologically functional role for UPE is the extremely low intensity. However, as quantum biology expands to consider non-linear optical phenomena, effects such as superradiance are attracting growing interest. These collective light–matter interactions could provide mechanisms through which initially weak photon signals become enhanced within organisms, increasing their effective biological impact. If such processes occur in living systems, they may help explain how ultraweak emissions participate in cellular communication and regulation, challenging the view that biophotons are merely incidental metabolic by-products. Another canonical topic in quantum biology is the radical pair mechanism, most famously used as a model to explain the avian compass, and more recently, applied to the production and balance of reactive oxygen species (ROS). The oxidative metabolic and stress-response processes that generate ROS are also implicated in the production of UPE. This would suggest a fruitful overlap of spin chemistry with UPE research and open a line of investigation as to whether magnetic field effects mediated through radical pairs have any influence on UPE production. In this short Perspective paper we will expand on these intersections between two fields that have had surprisingly little conversation between them.