纸基微流控技术及其在食品安全检测中的研究进展

Application Advances of Paper-based Microfluidic Analytical Devices in Food Safety Inspection

纸基微流控技术(μPADs)是一种在微米尺度的纸基芯片上进行样品制备、反应、分离、检测的技术,具有材料便宜、制作简单、易回收、结构多样、试剂消耗少、环保可降解等特点,在食品安全快速检测领域具有实用价值。该文对纸芯片制备、流体操控及检测模式进行了介绍。首先阐述了纸芯片功能化改性方法及生物分子的固定方式,总结了经处理后的纸张制备为二维(2D)或三维(3D)纸芯片的方法;其次论述了流体在纸基材料上不完全浸湿和完全浸湿两个阶段的运输机理,综合分析了智能化流体操纵技术;最后介绍了可与纸基微流控平台联用的检测方法,并综述了纸基微流控装置在食品安全检测中的应用研究进展,提出纸基微流控技术在食品行业未来面临的挑战及发展趋势。

Paper-based microfluidic analytical devices(μPADs)are a kind of technology for sample preparation,reaction,separation,and detection on paper chips,which have been widely used in biomedical,environmental,clinical analysis,chemical and other fields owing to their advantages,such as inexpensive production,simple fabrication,easy recycle,diverse structures,low reagent consumption,environmentally-friendly and biodegradation.In addition,they have the advantage of high sensitivity,which could be used by non-professionals to obtain the test results quickly,so they also exhibit a great practical value and a development potential in the rapid detection of food safety.This review highlights the recent advances on fabrication of paper chips,fluid transportation and control,and signal detection modes from the technical level.Firstly,this paper roughly describes the functional modification methods for paper chips with rich hydroxyl groups and high hydrophilicity,such as lithography,wax techniques,inkjet printing,screen printing,flexographic printing,3D printing,stamping,polydimethylsiloxane(PDMS)and other methods.Then three immobilization ways of biosensor molecules on paper-based materials,including physical adsorption,embedding and chemical immobilization are described.According to the direction of fluid flow(horizontal direction or vertical horizontal direction),the methods for preparing the processed paper into two-dimensional(2D)or three-dimensional(3D)paper chips are summarized.Secondly,the transport mechanism of fluid in two stages of incomplete soaking and complete soaking on paper based materials is discussed,incomplete soaking stage refers to the fluid on the paper based materials in the slow penetration of the paper,while complete soaking stage is when the fluid fills the paper based materials and is transported by capillarity.Moreover,this paper comprehensively analyzes the intelligent fluid manipulation technology,which can transport reagents and samples to the corresponding area within the appropriate detection time.Fluid transportation and control methods can be divided into passive device and active device.Passive device is simple and easy to manufacture without additional equipment,while active device relies on external input system and can achieve accurate multistep fluid flow control.Finally,this review introduces several detection methods that could be combined with paper based microfluidic platform in detail,such as colorimetric,electrochemical,chemiluminescence and electrochemiluminescence,fluorescence,etc.Furthermore,the research progress of paper-based microfluidic technology in food hazardous molecules,foodborne pathogens,heavy metal contamination and other aspects is reviewed,and the challenges and development trends of paperbased microfluidic technology in the food industry are also proposed.