硅纳米线在生物传感器中的应用概述

Applications of Silicon Nanowires in Biosensors:A Review

硅纳米线(SiNW)作为一种新型一维纳米材料,具有高比表面积、高稳定性等特点,在传感器领域得到了重视和研究。随着硅纳米线制备工艺优化、修饰方式多样化,以硅纳米线为载体的生物传感器被应用到了金属离子检测、蛋白质检测等诸多领域,较为优良的生物兼容性为生物学研究中的单细胞动态、实时监测提供了途径,电学、光学等不同检测手段也促进了硅纳米线生物传感器的机制研究。在生物化学物质传感检测中,传感器的敏感性、专一性和稳定性是衡量其性能的重要指标。硅纳米线化学性质稳定,为传感器的制备提供了良好的平台,在不同的应用场景中,传感器对硅纳米线的表面修饰提出了较高的要求。为此,研究人员提出了不同的传感机制。在电学信号传感方式中,硅纳米线场效应管(SiNW-FET)通过测量硅纳米线表面电荷变化引发的电导率变化,实现了对目标物质的超灵敏检测。在光学信号传感方式中,荧光分子识别应用较广,当目标物质与受体结合后通过荧光的增强、猝灭,波长的移动等多种方式传递信号,响应较快、检测手段较为便捷。对硅纳米线场效应管生物传感器和硅纳米线荧光传感器的机制与应用进行了概述,对今后硅纳米线在生物传感领域的发展提出了展望。

Silicon nanowire(SiNW)is one of the one-dimensional nanomaterials,and has been emerged as the promising sensing materials due to large surface area to volume ratio and high stability.The research of SiNW in sensing field has received wide attention.With the development of SiNW synthesis techniques and modification methods,biosensors based on silicon nanowires are now introduced into many research areas,including the detection of metal ions,early protein biomarkers and drug screening.On the other hand,high biocompatibility and commercial feasibility of silicon nanowires provide the potential to dynamic and real-time monitoring of single cell.Meanwhile,the research on silicon-based biosensors reveals different mechanisms like electrical,optical methods.Sensitivity,specificity and stability are important indicators of sensors to measure the performance during the detection of biochemical substances.Stable chemical properties of silicon nanowires provide an ideal platform for the fabrication of sensors.However,the surface modification remains as one of the challenges when biosensors based on silicon nanowires are used for different application scenarios.Depending on different requirements for sensing,silicon-based biosensors with different sensing mechanisms have been proposed.In terms of biosensors based on electrical signals,SiNW field-effect transistor(SiNW-FET)has been widely studied,which achieves ultra-sensitive detection of target substances by detecting the output electrical signal of sensor through the conductivity change of nanowire induced by surface charge density.Among biosensors based on optical signals,SiNW-based fluorescent sensor achieves detection by measuring the change of fluorescence intensity or wavelength,enabling fast and convenient detection.In this paper,the applications of silicon nanowires in biosensors are summarized,and the sensing mechanisms of SiNW-FET and SiNW-based fluorescent sensor are discussed.Finally,the future research and development of silicon nanowires in biosensors are prospected.