摘要
表面增强拉曼散射(SERS)技术在农药残留的检测方面具有很大的潜力,但在痕量和定量分析方面仍存在局限性。提出了一种基于Au@4-ATP@Au凸多面纳米颗粒(NCPs-Au@4-ATP@Au)为增强基底的农药检测方法。XRD结果表明,由于探针分子对金前驱的选择性和诱导性,NCPs-Au@4-ATP@Au纳米颗粒与球形金纳米颗粒晶面结构信息有明显差异,具体体现在(200)处的强反射峰。结合扫描电镜与吸收光谱可以确定,NCPs-Au@4-ATP@Au同时具备球形与多面体结构特征。吸收峰较球形金纳米颗粒有明显红移,更加接近激发光波长,这在理论上更有利于SERS信号的增强。实验证明,以表面包覆高指数晶面,同时内嵌4-ATP作为探针分子的NCPs-Au@4-ATP@Au为增强基底,农药多菌灵(CBZ)的检测限(LODs)达到0.66 nmol·L^(-1)。通过对CBZ分子的拉曼与SERS光谱位移分析可以初步确定,CBZ分子是通过NH键和CO键吸附于金纳米颗粒上。Au@4-ATP@Au利用多凸面结构体提高灵敏度的同时,以4-ATP作为定标信号,归一后光谱稳定性和时效性也得到改善。内标峰强度矫正后光谱稳定性的相对标准偏差(relative standard deviation,RSD)低至7.03%,半个月内信号强度仅降低5.87%,RSD为2.94%。结果表明,NCPs-Au@4-ATP@Au提高了SERS在农药检测方面的痕量和定量检测能力,该基底有望推动SERS在实际中的应用。
Surface Enhanced Raman Scattering(SERS)technology has great potential in detecting pesticide residues,but there are still limitations in trace and quantitative analysis.This paper proposes a pesticide detection strategy based on nano scale convex polyhedrons Au@4-ATP@Au(NCPs-Au@4-ATP@Au).XRD results showed that because of the selectivity and inductance of probe molecules to gold precursors,the crystal surface structure information of NCPs-Au@4-ATP@Au nanoparticles and spherical gold nanoparticles is significantly different,which is reflected in the strong reflection peak at(200).Combined with SEM and absorption spectrum,it can be determined that NCPs-Au@4-ATP@Au has both spherical and polyhedral structure characteristics.Compared with spherical gold nanoparticles,the absorption peak was significantly red shifted and closer to the wavelength of excited light,which was theoretically more conducive to enhancing the SERS signal.Experiments showed with NCPs-Au@4-ATP@Au,which was coated with high index crystal surface and embedded with probe molecule 4-ATP as the enhanced substrate,the Limits of detection(LODs)of Carbendazim(CBZ)reached 0.66 nmol·L^(-1).According to the Raman and SERS spectral shift CBZ molecules,it can be preliminarily confirmed that CBZ molecules are adsorbed to gold nanoparticles through the NH bond andCObond.Au@4-ATP@Au improved the sensitivity because of the multi-convex structure.Meanwhile,with 4-ATP as the calibration signal,the spectral stability and timeliness were also improved.After normalization,spectral stability's relative standard deviation(RSD)was as low as 7.03%,the signal intensity decreased by 5.87%,and RSD was 2.94%in half a month.The results showed that NCPs-Au@4-ATP@Au improved the trace and quantitative detection ability of SERS in detecting pesticides,and the substrate is expected to promote the practical application of SERS.
作者
严霞
胡聪聪
杨智远
赵航
史晓凤
马君
YAN Xia;HU Cong-cong;YANG Zhi-yuan;ZHAO Hang;SHI Xiao-feng;MA Jun(Department of Physics and Electronic Information Engineering,Lyuliang University,Lüliang 033000,China;Optics and Optoelectronics Laboratory,Ocean University of China,Qingdao 266100,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2024年第7期1843-1851,共9页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(42206191)
引进博士科研启动项目(0304407)
山西省基础研究计划项目(202303021222254)
吕梁市引进高层次科技人才重点研发项目(2023RC10)
2023年博士科研奖励项目(03051255)资助。
关键词
表面增强拉曼散射
多菌灵
凸多面纳米颗粒
定量分析
内定标
Surface-enhanced Raman scattering(SERS)
Carbendazim(CBZ)
Nanoscale convex polyhedrons
Quantitative analysis
Embedded probe
