Recent Developments in Innovative Magnetic Nanoparticles-Based Immunoassays: From Improvement of Conventional Immunoassays to Diagnosis of COVID-19

Abstract

During the ongoing COVID-19 pandemic, the development of point-of-care (POC) detection with high sensitivity and rapid detection time is urgently needed to prevent transmission of infectious diseases. Magnetic nanoparticles (MNPs) have been considered attractive materials for enhancing sensitivity and reducing the detection time of conventional immunoassays due to their unique properties including magnetic behavior, high surface area, excellent stability, and easy biocompatibility. In addition, detecting target analytes through color development is necessary for user-friendly POC detection. In this review, recent advances in different types of MNPs-based immunoassays such as improvement of the conventional enzyme-linked immunosorbent assay (ELISA), immunoassays based on the peroxidase-like activity of MNPs and based on the dually labeled MNPs, filtration method, and lateral-flow immunoassay are described and we analyze the advantages and strategies of each method. Furthermore, immunoassays incorporating MNPs for COVID-19 diagnosis through color development are also introduced, demonstrating that MNPs can become common tools for on-site diagnosis.

A vertically paired electrode for redox cycling and its application to immunoassays

“…7,39,40 At strongly acidic condition, the equilibrium between ox-TMB-1 and ox-TMB-2 was directed predominantly to the production of ox-TMB-2. 7,41 At first, the redox reaction of TMB at such different pH conditions was analyzed using the PEDOT:PSS electrode. As shown in Fig.…”

Lipid-based colloidal nanoparticles for applications in targeted vaccine delivery

“…1 Nanomedicine is an emerging branch of medicine that uses nanotechnology that can be tailored to specic diseases and target sites depending on the diagnosis, treatment, and prevention. [2][3][4][5][6][7] Nanotechnology research has gained popularity, and billions of dollars are spent on the development of goods incorporating nanotechnology each year. [8][9][10][11] Nanoparticles are advantageous because they can be tailored according to specic diagnostic or therapeutic applications due to their physiochemical properties and nanosize.…”

Molecular test for COVID-19 diagnosis based on a colorimetric genomagnetic assay

“…Magnetic beads (MBs) have also been applied to point-of-care testing due to their unique magnetic properties, high surface area, excellent stability, and easy biocompatibility [ 13 ]. The MBs can be coated with antibodies, oligonucleotides, or other molecules that bind specifically to the target, allowing an improvement in the sensitivity of detection from the magnetic pre-concentration of the target through redispersion in a small volume of the sample [ 14 , 15 ]. In this way, we combine the use of bioconjugate MBs with a specific probe to capture the SARS-CoV-2 RNA and a relatively simple colorimetric detection as a useful tool to diagnose and track the spread of SARS-CoV-2.…”