New Precision Engineering Methods for Low‐Cost Mass Production of Functional Giant Magnetic Glass‐Coated Particles as Immune Biomarkers

Advances in diverse diagnostic areas such as in vitro and molecular diagnoses have been stimulated by novel functional particles. In the industrialization stage of the diagnostic technology market, it is important to manufacture functional particles through low‐cost and large‐scale methods. Conventional methods in manufacturing magnetic particles typically involve modifying the surface of nano‐sized metal pieces with silica. These pieces are often suspended in a liquid state and difficult to separate, resulting in practical limitations during bioassay tests. A key factor in the manufacture of uniform magnetic particles is the mass production process. Herein, a new precision engineering method that focuses on rapid and cost‐effective mass production of uniform magnetic particles is presented, combining the cutting of magnetic microwires with electro‐opto‐micromachining techniques. The resulting giant magnetic glass‐coated particles have a high degree of uniformity and strong magnetic properties. They can be easily manipulated without the aid of a surfactant, and no particles are lost during bioassays. As biosensors, they offer high sensitivity and can be used in multiplexed immunoassays. A new precision engineering method for functional glass‐coated giant magnetic microparticles with low cost and mass production is demonstrated. This method can cut to submicron scale using ultra‐precision cutting technology, resulting in very high uniformity among particles. There is no particle loss or adsorption of the reactants. Giant magnetic glass‐coated particles have a high signal‐to‐noise ratio and can be used as a high‐sensitivity biomarker.