Paper Title
An Ultra-Sensitive Detection of cxcr4 in Human Liver Cancer Cells on Photonic Crystal Surface

Amplification of fluorescence intensity is of important role to the development of chemical and biochemical imaging and sensing. Here, we report the fluorescence enhancement from Cyanine-5 (Cy5) organic dye on the surface of three-dimensional photonic crystal. The enhancement is due to the overlapping between emission wavelength of organic dyes and photonic stop bands of photonic crystals. The fabricated three dimentional (3D) photonic crystals surface enhanced the fluorescence intensity by a factor up to 390- fold compared with Cy5 on an unpatterned glass surface. This platform is accessible to a wide range of users in an ordinary lab only by drop drying of poly styrene-co-N-isopropyl acrylamide p(St-co-NIPAM) spheres on the glass substrate. We applied the self-assembled colloidal photonic crystals (PhCs) platform for detecting CXCR4 in human liver cancer (HePG2) cells through sandwich immunoassay format. Index Terms- Cy5, Cy3 Organic dye, CXCR4,Fluorescence enhancement, photonic crystals