A synergistic biomimetic optical structure for household health monitoring

Abstract A breakthrough in the performance of bionic optical structures will only be achieved if we can obtain an in-depth understanding of the synergy mechanisms operating in natural optical structures and find ways to imitate them. In this work, inspired by feline eyes, an optical structure that takes advantage of a synergistic effect that occurs between resonant and reflective structures was designed. The reflective structure consists of anodic aluminum oxide with an aluminized inner layer (Al-AAO), and the resonant structure consists of three-dimensional (3D) graphene inside, and on the surface of the Al-AAO. The synergistic effect between the reflective and resonant components leads to a Raman enhancement factor (EF) of 1.16 × 107 which is much greater than that achieved using the reflective/resonant cavities on their own. A 2-3 order of magnitude increase in sensitivity could thus be achieved when used to detect model compounds. More importantly, the optical device was further used to develop a highly-sensitive household health monitoring system. The system uses simple apparatus (homemade centrifugal device and hand-held Raman spectrometer) and rapidly produces results (detection time＜3 min). It can thus be used to give early warning of acute diseases with high risk (e.g., acute myocardial infarction). The 3D-graphene/Al-AAO substrates were also found to have good reusability and storability (9% and 7% reduction in EF after washing 30 times and 8 weeks of storage, respectively). They thus reduce detection costs (to ~$1), making them much cheaper to use than the current gold-standard methods (e.g., ~$16 for gout detection).