Biomagnetic Neurosensors. 4. Design and Optimization for Analytical Use

Abstract

Biomagnetic neurosensors based on magnetic stimulation and magnetic detection of neural events depend critically upon the effective matching of the magnetic transducers and the neural tissue employed. Although the properties of wire-wrapped ferrite core transducers can be predicted from electromagnetic fundamentals, meaningful analytical measurements using real nerves as molecular recognition elements require additional calibration and optimization steps in order to achieve good system response and lifetimes. This note provides some design guidelines and experimental test procedures to enable potential users to employ biomagnetic neurosensors in other laboratories.

Strategies for Mimicking Olfaction: The Next Generation of Electronic Noses?

“…The prototype demonstrated the feasibility of the concept of receptor-based biosensors; however, problems of lifetime and limited detection range prevented the early``receptrode'' from being an analytically useful device. After several improvements and new developments (see Buch and Rechnitz 1989 [105]; Coon et al, 1996 [106]; Van Egeraat and Wikswo, 1991 [107] Schu Ètz et al 1996 and 1997 [108,109]), a biosensor for volatiles released by damaged plants was developed on the basis of insect antenna (Colorado potato beetle, Leptinotarsa decemlineata) using the far more rugged EAG technique in which summed dendrite potentials are recorded with two electrodes placed in the hemolymph space of the antenna. Experience of other groups could be used in designing portable EAG devices [110±112].…”

“…A decisive step in the direction of miniaturization and electrical stabilization of this biosensor type was the realization of extracellular recording with a direct FET-insect antenna junction (Figure 3.28 [108,109]). This more compact set-up combines the bene®t of miniaturization with the possibility to achieve increased life time because of the high impedance of the FET which needs only very little antenna injury during preparation.…”

“…Also shown is a reference electrode (left side). S denotes source, D drain, U RefDS the voltage of the reference electrode (drain source voltage) and I D the drain current(Schu Ètz et al, 1996; [108,109].…”

Neuronal Biosensors Using Liposomal Delivery of Local Anesthetics

“…The changes in the conduction ability of the nerve tissue can be measured by very sensitive transducing devices such as biomagnetic “inductrodes” (sensors that can measure changes in magnetic fields) or potentiometric electrodes . The transducing device used in this study is composed of two loose-clamp capillary electrodes positioned at the membrane of an excised section of nerve tissue (Figure ).…”