Detection of Dynabeads using a micro-electro-mechanical-systems fluxgate sensor

Abstract

This paper presents an approach to detect the presence of Dynabeads with a system based on a micro fluxgate sensor fabricated by micro-electro-mechanical systems technology. Due to the excellent performance of the micro fluxgate sensor, the detection system exhibited many advantages, such as lower minimum detectable limit, small weight, and low power consumption. Experimental results show that, applied an external magnetic field in a range of 430 μT to 600 μT, Dynabeads with a concentration as low as 0.1 μg/ml can be detected by this system. Moreover, the detection system could give an approximate quantitation to the magnetic beads.

Sandwich immunoassay for the prostate specific antigen using a micro-fluxgate and magnetic bead labels

“…Secondly, Dynabead magnetization was related to external magnetic field intensity and dispersion degree of Dynabead on the gold film. The high magnetic susceptibility of Dynabead magnetized by external magnetic field, the high enhance the intensity of weak magnetic field induced by the Dynabead, and that is beneficial to magnetic sensor detection [20,27]. At last, if the matrix effects were weakened by means of immuno-magnetic separation (IMS) technology [35], the detection sensitivity can be further enhanced.…”

“…Micro fluxgate fabricated by microfabrication technology can overcome those barriers. The micro fluxgate possesses advantages such as low power, light weight, compatible with interface circuits and integrated with microfluidic chip [20]. Thus, biosensor using micro fluxgate is very suitable in biomarker detection [21].…”

An innovative detecting way of Escherichia coli O157H:H7 by a micro-fluxgate-based bio-sensing system

“…It should be noted that magnetization is related to the distance from the magnetic substrate and was significantly reduce from the utilization of MEMS technologies. This can be further enhanced to further improve the detection capability of the bio-sensing system [31]. Fig.…”

Detection of Dynabeads in small bias magnetic field by a micro fluxgate-based sensing system

“…[19][20][21][22] Many micro fluxgate sensors using MEMS technologies have been developed and have the attractive features of small size, light weight, high sensitivity, high resolution, integration of signal processing circuits, etc. [23][24][25][26][27][28] In our previous works, using a MEMS fluxgate-based sensing system, we had detected Dynabeads with a concentration as low as 0.1 lg/ml of 10 ll (approximately 90 beads, corresponding to 1 ng Dynabeads or 0.12 ng Fe) by applying a bias magnetic field of above 450 lT. 29,30 We found the max signal difference of Dynabeads detection based on static response method happens at 550 lT, near the saturation field of the micro fluxgate sensor.…”