Advanced materials for drug delivery and biosensors based on magnetic label detection

Many traditional magnetic materials are not suitable for the increasing demands of microsensors for environmental control, biomedical applications, drug delivery, and homeland security. The design of magnetic biosensors can be based on different types of magnetic effects. The detection principles are measurements of the resistance, impedance, etc. in the absence and presence of magnetic nanoparticles. Variations in the measured parameters can be associated with either many individual molecular recognition events or with a specific uptake. Magnetic materials which could be used in magnetoimpedance based biosensors have been studied both for the sensitive element and for magnetic label. The self-assembling processes were observed in perpendicular field for different concentrations of the Dynabeads® M-480. Magnetic field controlled assembly is proposed for designing new composite materials which can be also useful to study the properties of the separate particles. The morphology of the particle agglomerates and dipolar chains in the external field can be controlled by using simultaneously two different suspensions of magnetic particles. A new concept is to define synergetic combinations of two or more nanostructures for the best performance.