Magnetic frequency mixing technological advances for the practical improvement of point‐of‐care testing

Abstract

Nanomaterials, especially superparamagnetic nanomaterials, have recently played essential roles in point-of-care testing due to their intrinsic magnetic, electrochemical, and optical properties. The inherent superparamagnetism of magnetic nanoparticles makes them highly sensitive for quantitative detection. Among the various magnetic detection technologies, frequency mixing technology (FMT) technology is an emerging detection technique in the nanomedical field. FMT sensors have high potential for development in the field of biomedical quantitative detection due to their simple structure, and they are not limited to the materials used. In particular, they can be applied for large-scale disease screening, early tumor marker detection, and low-dose drug detection. This review summarizes the principles of FMT and recent advances in the fields of immunoadsorption, lateral flow assay detection, magnetic imaging, and magnetic nanoparticles recognition. The advantages and limitations of FMT sensors for robust, ultrasensitive biosensing are highlighted. Finally, the future requirements and challenges in the development of this technology are described. This review provides further insights for researchers to inspire the future development of FMT by integration into biosensing and devices with a broad field of applications in analytical sensing and clinical usage.frequency mixing technology (FMT), lateral flow assay (LFA), magnetic imaging, magnetic nanoparticles (MNPs), point-of-care testing (POCT) | INTRODUCTIONRapid medical diagnosis is difficult using current laboratory testing techniques and their application is hindered by factors such as equipment requirements, operator capabilities, and the testing time.In particular, there is an increasing demand for rapid, convenient, and high precision medical diagnosis techniques for detecting coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome (SARS), and other highly contagious infectious diseases (Alfadly et al., 2020;Chu et al., 2021;X. Dong et al., 2021). Point-of-care testing (POCT) can be used for in vitro clinical testing and diagnosis (Wei et al., 2021;Yan et al., 2019). POCT usually refers to detection techniques that do not require a professional operator to perform tests at the bedside next to the patient (Nichols, 2003;Wang et al., 2021;Xia et al., 2016). POCT is characterized by rapid analysis at the sampling site, and thus complicated laboratory processing procedures are not required (Sharma et al., 2021). POCT methods might not have the same level of sensitivity and accuracy compared with laboratory-level medical diagnosis techniques. However, with the advantages of its simple implementation and lack of requirement for professional operational support, this technology receives widespread attention in countries and regions, especially those with a low level of

Magnetic nanoprobe-enabled lateral flow assays: recent advances

“…Consequently, in future studies, it is necessary to consider the impact of coil parameter changes on the performance induced by the use of strip steel shells. 24…”

“…Consequently, in future studies, it is necessary to consider the impact of coil parameter changes on the performance induced by the use of strip steel shells. 24 Znoyko et al utilized the biotin-streptavidin high-affinity interaction for the quick trapping of MP on the TL in 2018 to increase the detection potential of FMT in LFIA. The combination of this approach with the MPQ reader significantly improved IC detection sensitivity over short periods, achieving a greater detection range, and thyroxine (fT4) breached the 20 fM detection limit.…”

“…23 Currently, a variety of MNPs signal detection strategies have emerged, including magnetoresistance, magnetic flux, and, magnetic permeability. 24 Thus, several different detection methods have been developed: giant magnetoresistance (GMR), anisotropic magnetoresistance (AMR), and tunneling magnetoresistance (TMR) 25 methods based on magnetoresistance; magnetic assay reader (MAR) 26,27 method based on magnetic flux; magnetic particle quantification (MPQ) method based on frequency mixing technology (FMT); 28 magnetic resonance coil magnetometer (RCM) method based on magnetic permeability.…”

Quantum‐Based Magnetic Field Sensors for Biosensing

“…A technique named microfluidicscanning SQUID microscopy was proposed for high-throughput MNP screening with 0.1 × 10 −18 m sensitivity, [12] which is important for large-scale disease screening, early multitumor marker detection, and low-dose drug detection. [10,160,161] Therefore, the fabrication of SQUID on the nanometer scale is a crucial requirement to achieve the necessary flux sensitivity and spatial resolution, which can be achieved by electron beam lithography or focused ion beam integration with thin film deposition, microlithography, etching, bonding, polishing, and other standard microfabrication technologies. [85] For SERF atomic magnetometers, although they show advantages in miniaturization and independence from cryogenic liquids, more efforts should be devoted to sensitivity improvement, magnetic shielding, and chip-scale design.…”

A sensitive electrochemical platform integrated with a 3D graphene aerogel for point-of-care testing for tumor markers

“…Various POCT platforms have been developed and used to detect tumor markers, among which electrochemical-based POCT platforms have received special attention due to their high sensitivity, high specificity and rapid detection. [10][11][12][13] However, the current electrochemical POCT platforms still have some challenges, especially in achieving miniaturization. Recently, microfluidic devices have been widely investigated in the detection of multiple tumor markers.…”