Can a single ligand-receptor simultaneously sense multiple environmental information?

Yes. Cell receptor sensors provide perfect examples of information transduction in the presence of non-negligible thermal fluctuations. Previous studies on cellular sensing have focused on minimizing the noise's impact on the accuracy of concentration sensing in ligand-receptors. However, we discovered that the thermal noise is not always an adversary -- it could allow a single sensor to simultaneously receive multiple channels of environmental information (e.g., simultaneously sensing concentration, temperature, and flow speed). With minimal models of a single receptor in a Langevin bath of ligands, we demonstrate that a single receptor can simultaneously measure the ligand concentration, temperature, and flow speed (if the bath has a nonzero flow speed). Furthermore, we obtained the theoretical upper bound of informational bandwidth of a single ligand-receptor (e.g., how many environmental properties can a receptor simultaneously sense). Our results provide insights on designing novel microscopic sensors that operate in realistic and complex environments.