Recognizing the need to bring down the cost and improve the performance of chip-based biosensors for use at the point of care to detect cancer and other diseases, researchers at the Harbin Institute of Technology (Shenzhen, China) have developed a way to inject light into silicon microdisks. The method could eventually lead to a portable, low-cost optical biosensor for early-stage cancer diagnostics.
Microdisks are a type of microscale resonator that use the whispering-gallery optical effect to confine and enhance light that enters the disk. This allows the microdisk to boost a light-based signal coming from a cell, protein, or virus of interest, allowing more sensitive detection of subtle changes associated with diseases such as lupus, fibromyalgia, and certain heart problems. Research team leader Qinghai Song explains that whispering gallery mode microresonators exist that can be used to resolve single molecules, but their application is limited by problems in device repeatability, stability, and wavelength range. The research team’s design, however, works with a variety of wavelengths with low cost, higher stability, and better device repeatability, he claims.