A microarray chip based on photonic crystals and fluorescence amplification for discrimination of Baijiu
An accurate, effective, and convenient method for identification of Baijiu (a distilled liquor popular in China) components could be important for its commercial management. Herein, we report, for the first time, a fluorescence-amplifying sensor array chip based on photonic crystals (PCs) employed to identify Baijiu components. Transmission electron microscopy and scanning electron microscopy were employed to characterize polystyrene microspheres and PCs, which exhibited characteristic uniform and compact arrangements. A spotting machine and fluorescence scanner were used for dye loading and data collection. Array performance was evaluated by pattern recognition and neural-network simulation. Our array chip was manufactured successfully and revealed outstanding discriminative ability for Baijiu. Compared with other liquid sensor arrays used only for configuration, our array chip possessed >90% leave-one-out accuracy after 10 days of dry storage under a N2 atmosphere. This simple and accurate method shows potential for quality control and detection in factories/markets.