Title :
Noise Characteristics and Particle Detection Limits in Diode+MTJ Matrix Elements for Biochip Applications
Author :
Cardoso, F.A. ; Ferreira, R. ; Cardoso, S. ; Conde, J.P. ; Chu, V. ; Freitas, P.P. ; Germano, J. ; Almeida, T. ; Sousa, L. ; Piedade, M.S.
Author_Institution :
1Instituto Nacional de Engenharia de Sistemas a Computadores-Microsistemas a Nanotecnologias, Lisbon
fDate :
6/1/2007 12:00:00 AM
Abstract :
A fully scalable matrix-based magnetoresistive biochip has been recently introduced for the detection of biomolecular recognition events. This work reports results for a 3times3 cells matrix comprising hydrogenated amorphous silicon diodes (PIN and Schottky) and aluminum oxide magnetic tunnel junctions (MTJ). The noise characteristics of the individual thin film diodes (TFD) and the MTJ were analyzed for measuring frequencies from DC to 1 kHz, allowing the detection of single magnetic nanoparticles with 250 nm and 130 nm diameters. For 50 nm particles, and at 1 kHz, minimum number of detectable labels ranges from 20 (Schottky diodes) to 50 (PIN diodes).
Keywords :
Schottky diodes; aluminium compounds; amorphous semiconductors; biological techniques; biomagnetism; elemental semiconductors; magnetic particles; magnetic sensors; magnetic tunnelling; magnetoresistive devices; molecular biophysics; nanoparticles; noise; p-i-n diodes; silicon; thin film sensors; 1 kHz; 130 nm; 250 nm; 50 nm; AlO; PIN diode; Schottky diode; Si; aluminum oxide magnetic tunnel junctions; biochip applications; biomolecular recognition events; hydrogenated amorphous silicon diodes; magnetic nanoparticles; matrix-based magnetoresistive biochip; noise characteristics; particle detection limits; thin film diodes; Aluminum oxide; Amorphous silicon; Event detection; Frequency measurement; Magnetic analysis; Magnetic films; Magnetic noise; Magnetic tunneling; Magnetoresistance; Schottky diodes; DNA-chips; magnetic nanoparticles; magnetic tunnel junction; magnetoresistive biochips;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2007.893705
