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

Magnetite nanoparticles prepared by co-precipitation method in different conditions

“…Generally, the unit cell of magnetite has 32 oxygen atoms and 24 Fe atoms; the latter are Fe 2þ and Fe 3þ on octahedral and tetrahedral sites. Their distribution among the octahedral sites is random and fluctuating [23]. It is a ferrimagnet so there is also competition between the sub lattices, and it is far from easy to tell how the absence of a set of neighbours would affect the alignment and modify magnetic properties.…”

“…[21]. Another simple example of such a functional material is the commercially available magnetic Dynabeads ® widely used for magnetic separation [22,23]. The Dynabeads ® M-450 are magnetisable superparamagnetic polystyrene beads of 4.5 microns in diameter consisting of nanometer-sized iron oxide particles embedded in a polymer matrix.…”

Advanced Magnetic Microwires as Sensing Elements for LC-Resonant-Type Magnetoimpedance Sensors: A Comprehensive Review

“…Some prototype sensors employing these materials as sensing elements, i.e., magnetic field sensors [46][47][48][49][50], current sensors [51,52], position sensors [53,54], stress sensors [55,56], torque sensor [57], biosensors [58][59][60][61][62][63], were proposed and successfully developed. The current progress of GMI is thrusted toward the increase of magnetic-field sensitivity and the optimization of the signal-to-noise ratio in the GMI sensor devices [64,65].…”

Giant magnetoimpedance for biosensing: Advantages and shortcomings

“…MI magnetic field sensors adapted for the detection of magnetic markers are still under development: all prototypes which have been reported until now, instead of employing of a suitable biochemistry to count the selectively attached markers, deal with free beads immersed in a buffer [9][10][11][12][13] or spread on the surface of the MI sensitive element ''in dry'' [14]. These prototypes were based on rapidly quenched amorphous ribbons [9,11,13], rapidly quenched wire [14], glass covered microwires [12,14] or MI multilayers [10]. Ribbon-based MI elements, which are inexpensive, very sensitive to external field detectors work in relatively low-frequency range well adapted to standard electronic circuitry solutions of 1-10 MHz.…”