BIOMAGNETIC NEUROSENSORS

In this report we demonstrate the first analytical application of biom agnetic field detection at nerve fibers for biosensing purposes. A fer rite core toroid surrounding the nerve, coupled to a low-noise, low-in put-impedance amplifier, is used to inductively detect the compound, a ction current (CAC) in crayfish giant axons upon stimulation of nerve firing. Detection of the local anesthetic lidocaine, which blocks neur onal conduction by binding in the ion channel of the voltage-gated sod ium channel receptor, is achieved by monitoring the disappearance of t he CAC. The application of this novel detection principle to the scree ning of neurotoxic and neuromodulatory drugs and natural product extra cts is proposed.