Lattice-parameter-controlled sensitivities of imprinted photonic crystals for BPA detection

• Main Authors: Fang, Chih-Hsiang, 方峙翔
• Other Authors: Chang, Sue-Min
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/57743510136412379233

碩士 === 國立交通大學 === 環境工程系所 === 102 === In this study, a high sensitive and quick responsive ZrO2 imprinted photonic crystal (IPC) for detection of BPA was developed. The diffraction wavelength shift, resulting from the changes in the refractive index(n) of the IPC after rebinding of BPA, is used for the quantification of the target compound. Polystyrene(PS) microspheres with the sizes in the range of 235-285 nm as the template for inverse opal photonic crystals were prepared using emulsion free and emulsion polymerization method. They self-assembled into opal structure through a heat-assisted method at 50C. Imprinted precursor solution, containing phenyltrimethoxysilane (PTMOS) as the functional monomer and zirconium propoxide (ZPO) as cross-linker in the molar ratio of PTMOS/BPA/ZPO/EtOH molar ratio of 1/1/30/80, was infilitraed into the void of the colloidal crystals in N2. Hydrolysis of the precursor solution at a high temperature (60C) and high hymidity (relative humidity: 100 %) leads the imprinted cavities generating at the surface more than in the bulk. The IPC reached an adsorbtion equilibrium within 20 min in 50 mg/L BPA solution, and wavelength shifted from 4.5 to 6.3 nm when the pore diameters increased from 160 to 200 nm (correspondingly the PS size increased from 235 to 305 nm). The optimal IPC exhited two linear rages in 0.5-1.0 mg/L and 1.0-90.0 mg/L, and the detection limit was 0.50 mg/L. Insignificant response for BPA analogues indicates its high selectivity. These results clearly demonstrated that the IPC has high sensitivity and quick response which is promising for in-situ and on-site analysis in the future.