Can an immunoassay be designed to identify a virus in less than 5 minutes? A recent study indicates that this is feasible using a low-power laser, similar to a laser pointer, along with a tiny liquid sample comparable to a sesame seed.
Just like moths are drawn to light, microbes can also be manipulated using light. With this concept in mind, researchers from Osaka Metropolitan University’s Research Institute for Light-induced Acceleration System (RILACS) have introduced a technique for the swift detection of viruses using minimal sample sizes.
The team, headed by OMU Professor Takuya Iida, who directs RILACS, along with Associate Professor Shiho Tokonami, the deputy director, reports their findings in npj Biosensing regarding a light-induced immunoassay. They utilized laser exposure for less than one minute to facilitate the coating of a nanoparticle-imprinted plasmonic substrate, which features small nanobowl structures each measuring 500 nanometers in diameter, with antibodies targeting the spike proteins of the novel coronavirus. Using a 5-milliwatt laser, comparable in power to standard laser pointers, they were able to generate bubbles on the biochip that attracted virus-mimicking nanoparticles, thereby speeding up the selective detection of these particles.
Thanks to light-induced convection, the nanoparticles are effectively moved to collect at the still area between the substrate surface and the base of the bubble, which means that a high concentration of particles isn’t needed. The overall process, from substrate coating to detection, can be wrapped up in under 5 minutes.
“This research demonstrates that we can simplify the lengthy antibody coating procedure and achieve fast, sensitive protein detection,” stated Professor Iida. “We believe our discoveries could aid in the early diagnosis of not only the novel coronavirus, but also various infectious diseases, cancer, and even dementia.”
