标题：Diatomite Photonic Crystals for Facile On-Chip Chromatography and Sensing of Harmful Ingredients from Food
作者：Kong, Xianming; Yu, Qian; Li, Erwen; Wang, Rui; Liu, Qing; Wang, Alan X.
作者机构：[Kong, Xianming; Yu, Qian; Wang, Rui] Liaoning Shihua Univ, Coll Chem Chem Engn & Environm Engn, Fushun 113001, Liaoning, Peoples R China.; [Li, Erw 更多
通讯作者地址：[Yu, Q]Liaoning Shihua Univ, Coll Chem Chem Engn & Environm Engn, Fushun 113001, Liaoning, Peoples R China;[Wang, AX]Oregon State Univ, Sch Elect Engn 更多
关键词：diatomite; photonic crystal biosilica; on-chip chromatography; SERS;; food product
摘要：Diatomaceous earth-otherwise called diatomite-is essentially composed of hydrated biosilica with periodic nanopores. Diatomite is derived from fossilized remains of diatom frustules and possesses photonic-crystal features. In this paper, diatomite simultaneously functions as the matrix of the chromatography plate and the substrate for surface- enhanced Raman scattering (SERS), by which the photonic crystal-features could enhance the optical field intensity. The on-chip separation performance of the device was confirmed by separating and detecting industrial dye (Sudan I) in an artificial aqueous mixture containing 4-mercaptobenzoic acid (MBA), where concentrated plasmonic Au colloid was casted onto the analyte spot for SERS measurement. The plasmonic-photonic hybrid mode between the Au nanoparticles (NP) and the diatomite layer could supply nearly 10 times the increment of SERS signal (MBA) intensity compared to the common silica gel chromatography plate. Furthermore, this lab-on-a-chip photonic crystal device was employed for food safety sensing in real samples and successfully monitored histamine in salmon and tuna. This on-chip food sensor can be used as a cheap, robust, and portable sensing platform for monitoring for histamine or other harmful ingredients at trace levels in food products.