Magnetic Nanomaterials in Microfluidic Sensors for Virus Detection: A Review

Magnetic nanomaterials (MNMs) have gained great interest from different fields of study ranging from wastewater treatment to (bio)sensor development, taking advantage of both nanoscale size (allowing high surface-to-volume ratios) and the opportunity for magnetic manipulation. These materials can be surface-modified with antibodies, oligonucleotides, and aptamers to enable selective binding with target viruses or their biomarkers in biological samples. Using an external magnetic field, MNM-virus/biomarker complexes can be effectively isolated for further analysis. In some cases, the role of MNMs is not limited to simply serve as magnetic sorbents for extraction purposes as they have become an active part of some emerging detection processes (e.g., the use of magnetoresistive sensors). The combined application of MNMs with microfluidics for virus detection provides promising avenues for diagnostic tests that are of lower cost, require less time, and have higher specificity and sensitivity over conventional tests. This review focuses on the different approaches of virus detection using MNMs integrated in microfluidic chips. We will discuss recent research findings and provide insights and future perspectives for the development of low-cost and effective COVID-19 diagnostics tests.