Proteins and Patients — Magnetic Nanoparticles as Analytic Markers

Abstract

Exciting new applications of low noise magnetic sensors in biotechnology, medical diagnosis and therapy are at hand for magnetic nanoparticles (MNP), which are already used in the clinical routine. The relaxation of magnetic nanoparticles is a fascinating method which can be employed for the characterization of ferrofluids and is further developed as analytical tool for biochemistry. In this article the basics and methods of the characterization of diluted ferrofluids by magnetore-laxometry (MRX) are described. We start with the properties of the ferrofluid which consists of magnetic nanoparticles. The time schedule for relaxation measurements is discussed. The details of our fluxgate based experimental set-up are presented. To achieve high sensitivity even at low concentrations of magnetic nanoparticles we optimize fluxgate sensors for low intrinsic noise, high sensitivity and large bandwidth.