Surface modified amorphous ribbon based magnetoimpedance biosensor

Abstract

Magnetoimpedance (MI) changes due to surface modification of the sensitive element caused by human urine, were studied with the aim of creating a robust biosensor working on a principle of electrochemical magnetoimpedance spectroscopy. A biosensor prototype with an as-quenched amorphous ribbon sensitive element was designed and calibrated for a frequency range of 0.5-10 MHz at a current intensity of 60 mA. Measurements as a function of the exposure time were made both in a regime where chemical surface modification and MI measurements were separated as well as in a regime where they were done simultaneously. The MI variation was explained by the change of the surface magnetic anisotropy. It was shown that the magnetoimpedance effect can be successfully employed as a new option to probe the electric features of the Fe(5)Co(70)Si(15)B(10) amorphous ribbon magnetic electrode surface modified by human urine.

Corrosion Behaviour of Fe/Co Based Amorphous Metallic Alloys in Saline Solutions: New Materials for GMI Based Biosensors

“…Desde el descubrimiento por Yoshizawa et al [3] de la aleación de tipo FINEMET, Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 , como material magnético blando de excelentes propiedades (elevada magnetización de saturación, muy baja coercitividad, elevada permeabilidad), los materiales magnéticos amorfos obtenidos por esta técnica, han sido objeto de numerosas investigaciones en este campo, y en especial las aleaciones metálicas amorfas de base Co. Algunos de los requerimientos de esta nueva generación de biosensores, son una alta sensibilidad, pequeño tamaño, bajo consumo energético, estabilidad de operación, rápida respuesta y resistencia a la corrosión en medios agresivos. Las aleaciones metálicas amorfas que muestran efectos de magnetoimpedancia gigante, son materiales que pueden ser utilizados como elementos magnéticos sensibles para biosensores, ya que presentan una elevada sensibilidad frente a un campo magnético, como es el caso de la aleación Co 67 Fe 4 (muestra B). A partir de estas aleaciones, y mediante la técnica de solidificación ultrarrápida, se obtuvieron aleaciones metálicas amorfas de aproximadamente 10 mm de ancho y 20-30 µm de espesor.…”

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].…”

Cytotoxicity and GMI bio-sensor detection of maghemite nanoparticles internalized into cells

“…The presence of these particles in biological systems studied can be identified with the aid of suitable sensitive elements (biosensors) which are of interest for the magnetic bio-detection because of their high sensitivity, small size, low power consumption, quick response and low price. Following giant magneto-resistance (GMR) biosensors in bio-detection [2,3], giant magneto-impedance (GMI) sensors are also sensitive to low magnetic fields and present smaller power dissipation as recently reported [4][5][6][7][8].…”