Environmental effects on muonium adducts of lidocaine using avoided level crossing muon spin resonance

Lidocaine is a local anaesthetic, identified by the World Health Organisation as an essential medicine. In order to reach its site of action, lidocaine first has to pass from a watery environment outside a cell, through at least one cell membrane, the inside of which is oily. Water and oil are known not to mix, yet lidocaine traverses both! Although much is known about the interaction of lidocaine with membranes, typically this has been done with bulky labels that may affect the membrane. Muons, a type of subatomic particle, are able to interact with substances with certain structural features. Muons themselves weigh around 1/9 that of a proton and thus can act as ultrasensitive labels while not perturbing the system. This proposal explores how the signal generated by the interaction of lidocaine with muons is affected by its environment, including the effect of pH and solvent polarity.