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

Volume

43

Issue

6

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

2403

Lastpage

2405

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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2007.893705

Filename

4202663