摘要
表面增强拉曼散射(Surface-enhanced Raman scattering,SERS)是使吸附在粗糙金属表面分子的拉曼散射显著增强的现象。SERS效应主要是通过金属中的局域表面等离子体共振引起的电磁场增强。金、银纳米材料由于光激发产生的表面等离子共振效应可以显著增强SERS信号而被广泛用于SERS基底材料。但是在实际应用中,由于这类材料的精细纳米结构、表面粗糙度和聚集度无法精确控制,导致SERS检测稳定性和重复性不高。为此,研究者常通过引入内部标准或利用比值法来校准样品干扰和测量条件的信号波动等不可控因素引起的误差。或者是从根本上改善纳米材料的排列方式,例如,在互不相容的两相界面上因界面能的降低驱动纳米颗粒自上而下地自发组装成单层次有序结构。研究表明,液相界面纳米颗粒阵列的均匀性远优于纳米颗粒溶胶中颗粒的随机聚集或固体表面上的固定阵列。由于DNA具有特异性识别、末端可灵活修饰官能团及可逆结合等优势,不仅可以灵活调节SERS基底纳米颗粒间的间隙,还可以利用DNA结构的信号放大技术,进一步降低目标物的检测限。近年来,基于DNA结构与SERS技术相结合的生物传感器已经广泛应用于多种生物分子的定量检测。因此,为了改善SERS生物检测的稳定性和重现性,可以将SERS技术与DNA结构相结合,以构建具有突出SERS增强效果,信号稳定以及可实现高效灵敏检测生物分子的SERS传感平台。
Surface-enhanced Raman scattering(SERS)is the phenomenon that the Raman scattering of molecules adsorbed on rough metal surfaces was significantly enhanced.The main contribution to the SERS effect is the electromagnetic field enhancement mechanism induced by localized surface plasmon resonance in metals.Gold(or silver)nanomaterials are widely used as SERS substrate materials due to production of surface plasmon resonance,and nano-gaps and nano-voids can be formed through mutual coupling to significantly enhance the SERS signal.However,in practical applications,the fine nanostructure,surface roughness and aggregation of this kind of materials cannot be precisely controlled,resulting in poor SERS detection stability and repeatability.For this reason,researchers often reduce the background signal caused by inhomogeneity of SERS solid substrates through introducing internal standards or using the ratio method to calibrate the variance of uncontrollable factors such as sample interference and signal fluctuations of measurement conditions.Or radically improving the arrangement of nanomaterials,for example,by driving the top-down spontaneous assembly of nanoparticles into a monolayer ordered structure at the interface of incompatible two phases due to the reduction of interfacial energy.It is shown that the homogeneity of nanoparticle arrays at liquid-phase interfaces is much better than random aggregation in nanoparticle sols or stationary arrays on solid surfaces.Due to the advantages of specific recognition,flexible end modification and reversible binding of DNA,not only can the degree of uniformity of SERS substrate be flexibly adjusted as well as the nanogap can be adjusted,the distance between Raman molecules and SERS substrate can be adjusted to quantitatively detect the target,and the signal amplification technology of DNA structures can be used to further reduce the detection limit of the target.In recent years,biosensors based on the combination of DNA structures and SERS technology has been widely used for th
作者
吴彩骏
杨霞
Wu Cai-jun;Yang Xia(College of Chemistry and Chemical Engineering,Southwest University,ChongQing,400715,China)
出处
《化学传感器》
CAS
2020年第2期21-34,共14页
Chemical Sensors
基金
重庆市自然科学基金(cstc2019jcyj-msxmX0209)。
关键词
表面增强拉曼光谱
生物传感器
DNA技术
自组装界面
surface-enhanced raman scattering
biosensor
DNA technology
charge transfer
self-assembly interface
