RIfS干涉基底的制备、应用及展望

Preparation,Application and Prospect of RIfS Interference Substrates

反射干涉光谱(Reflectometric interference spectroscopy, RIfS)是一种利用白光干涉原理来对薄膜光学厚度进行测量的非标记检测技术。干涉基底作为RIfS系统的传感单元,是RIfS技术的核心部分,也是决定RIfS系统性能的关键。目前使用的干涉基底通常被分为两大类:一类是以无机氧化物或聚合物薄膜为代表的平面固体基底,另一类是以多孔硅(pSi)、纳米多孔阳极氧化铝(NAA)以及二氧化硅胶体晶体(SCC)为代表的多孔基底。平面固体基底制备简单且信号稳定,但是检测灵敏度通常比较低;多孔基底具有较大的比表面积,可以捕获更多待测分子,因此与平面固体基底相比检测灵敏度有所提高,并且具有更多的调节空间,非常适合生化传感平台的开发。从pSi到NAA再到SCC,多孔基底制备的可控性及传感性能不断提高,成为RIfS干涉基底的发展方向。本文对RIfS干涉基底发展现状进行了总结和讨论,阐述了基底的常用制备方法,总结了其在生物传感领域代表性的应用,重点讨论了不同基底的优缺点,并对干涉基底未来的发展进行了展望。

Reflectometric interference spectroscopy(RIfS)is a label-free detection technique by measuring the optical thickness of thin films which is based on white light interference.Interference effective substrates,as the sensor unit of the RIfS system,the construction of which is the core part of RIfS technology and the key to determining the performance of the RIfS system.Currently used interference substrates are generally divided into two categories:one is the planar solid substrates represented by inorganic oxides or polymer films,and the other is the porous substrates represented by porous silicon(pSi),nanoporous anodic alumina(NAA)and silica colloidal crystals(SCC).The preparation of planar solid substrate is simple and the signal is stable,but the detection sensitivity is usually low.In comparison with planar solid substrates,a porous substrate can provide a three-dimensional structure with a large specific surface area which will result in increased ligand immobilization density and capture of analyte.Therefore,the detection sensitivity is improved and there is more room for adjustment,which is very suitable for the development of a biochemical sensing platform.From pSi to NAA to SCC,the preparation controllability and sensing performance of porous substrates are continuously improved,which is considered a promising development direction of RIfS interference substrate.Here,the research status of RIfS interference substrates has been summarized and discussed,the common preparation methods of substrates are described,their representative applications in biosensing are summarized,the advantages and disadvantages of different substrates are discussed,and the future development directions of Rifs interference substrates has also been outlined.