新型磁性rGO-TiO_2-Fe_3O_4 SERS基底

A Novel Magnetic rGO-TiO_2-Fe_3O_4 SERS Substrate

SERS作为一种振动光谱,具有高灵敏度、高选择性、快速无损检测等优点,并且能提供丰富的分子指纹信息,广泛应用于分析化学、材料科学、生命科学等领域^([1])。因此,探究具有高SERS活性的基底成为了研究热点。半导体材料TiO_2由于其化学性质稳定、易得、无毒且具有较好的生物相容性,使其成为人们备受关注的SERS基底。然而,TiO_2相对较弱的SERS活性限制了其在SERS领域的发展。同时,SERS基底的聚集状态难于控制,直接影响其SERS性能的可重现性和稳定性。相关研究表明,对半导体TiO_2的适当改性可有效改善其表面活性,进而提高其SERS活性^([2])。因此,本文开展了强吸附能力的还原氧化石墨烯(rGO)和磁性Fe_3O_4修饰的TiO_2(rGO-TiO_2-Fe_3O_4)作为新型SERS活性基底的研究,实现了优良的SERS性能。磁性rGO-TiO_2-Fe_3O_4基底容易与探针分子分离,便于检测,对4-MBA分子的最低可检测浓度为10-9 mol·L^(-1),显著低于纯TiO_2基底(1.0×10^(-5) mol·L^(-1))。

As a vibrational spectrum,SERS is widely used in the field of analytical chemistry,materials science,life sciences,etc.,due to its high sensitivity,high selectivity,fast nondestructive testing and abundant fingerprint.So exploring the SERS substrate with high SERS activity has become a research hotspot.Semiconductor TiO2 nanomaterial has become the focus of SERS substrate,for it’s stable,easy to obtain,non-toxic and biocompatible properties.However,the relatively weak SERS activity of TiO2 limits its development in the SERS field.At the same time,the aggregation state of SERS substrate is difficult to control,and it directly affects the repeatability and stability of SERS performance.Relevant researches show that the appropriate modification of semiconductor TiO2 can improve its surface activity and further improve its SERS activity.Therefore,in this paper,a TiO2 modified by rGO and Fe3 O4 was used as novel SERS substrates to achieve excellent SERS performance.This magnetic rGO-TiO2-Fe3 O4 substrate is easy to be separated from the probe solution and is easy to detect.The minimum detectable concentration of the 4-MBA molecule is 10-9 mol·L-1,which is significantly lower than the pure TiO2 substrate(1.0×10-5 mol·L-1).