Preparation of a glucose-sensitive one-dimensional photonic crystal via top-down nanocasting

Photonic crystals have been widely explored for biosensing. However, the complicated procedure for the self-assembly of multi-dimensional photonic crystals has driven researchers to look for more economical protocols for preparing photonic crystals. Furthermore, in situ monitoring of glucose with photonic crystals is the main technique used for controlling diabetes. A one-dimensional (1-D) photonic crystal gel sensor was prepared with a top-down method using a commercially available CD-R or DVD-R disc as a nanomold. The 1-D photonic structure was cast on a glucose-sensitive hydrogel. It was observed that the 1-D photonic crystal cast by DVD-R has a good response ability to glucose, as well as a good linear response relationship in the range of 0.1-4 mM glucose, with an adjusted R² of 0.99 of the linear fitting curve. The sensor also has a good response ability to the detection of glucose in urine. The limit of detection (LOD) is 0.1 mM. The 1-D photonic crystal sensor utilizing the existing optical disc microstructure as a template shows the advantages of its simple preparation, short production cycle, and low cost. It also has great application potential in the preparation of point-of-care (POC) sensors.