A New Platform of Iron Oxide-Based Nanoparticles Assay Using GMR Chip-Based Sensor With Microcontroller

Abstract

The low-cost, simple, and fast quantitative assay of magnetic nanoparticles (MNPs) is important for the development of magnetic-based immunoassay applications. However, the bulky sensing element and instruments of the recent iron oxide-based MNPs assays are still concerns that should be resolved. This article reports the new platform of an iron oxide-based MNPs label assay using the commercial giant magnetoresistance (GMR) chip AAL024, manufactured by Nonvolatile Electronics (NVE) Corporation, complemented with a basic differential amplifier circuit and Arduino microcontroller (AM) to acquire the digital output voltage. The as-prepared Fe 3 O 4 @Ag label possessed (15 ± 2.6) nm of average size and behaved as soft ferromagnetic with 52.1 emu/g of saturation magnetization, and 0.15 kOe of coercive field. Sensor performance for magnetic field detection, as well as Fe 3 O 4 @Ag nanoparticles label assay, was evaluated. The results show the implementation of a basic differential amplifier op-amp circuit succeed to magnify the sensor's response to the magnetic field up to 23 times with the output voltage in the order of volt. The employment of the AM as a voltage supply of the GMR chip, an analog-to-digital converter, and a voltage gauge simplifies the data acquisition without the additional measuring instrument. Meanwhile, for the purpose of the Fe 3 O 4 @Ag nanoparticles label assay, the sensor revealed promising performance due to the high signal linearity and the rapid detection which is only 30 s with acceptable signal stabilities.

Review—Potential of Tunneling Magnetoresistance Coupled to Iron Oxide Nanoparticles as a Novel Transducer for Biosensors-on-Chip

“…84 Wibowo, et al suggested using an OA circuit with LM 358 as a basic differential amplifier to overcome the small output voltage of the MR chip. 40,85 OA ICs offer output voltage amplification circuit design freedom due to their high voltage gain (up to 100 dB). A differential amplifier suppresses simultaneous input voltages to increase the difference between two input voltages.…”

“…Numerous studies have been undertaken on this topic. 41,51,85,87,88 Wibowo, et al proposed the quantification method of silver-coated magnetite using a GMR chip manufactured by NVE Corp. 85 By using a similar chip, Ardiyanti, et al perform the successful quantification of GSmagnetite and streptavidin-coated MNPs. 41 Each research reveals the linear dependence of the sensor signal to the MNPs amount with the sensitivity in the order of mV/mg/mL.…”

Direct Detection of Green-Synthesized Fe₃O₄ Magnetic Nanotag Using Double-Chip Configuration of Commercial Giant Magnetoresistance Sensor

“…Their low output voltage requires expensive and heavy voltage meters, which restricts their availability and portability. At the same time, we also introduced a new platform for traditional chemical and green synthesis-based MNPs testing using only single-chip combined with a microprocessor and an amplifier circuit, producing a consistent and real-time signal [13,14].…”