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...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。展开更多
Raman spectroscopy is a noninvasive,nondestructive analytical method capable of determining the biochemical constituents based on molecular vibrations.It does not require sample preparation or pretreatment.However,the...Raman spectroscopy is a noninvasive,nondestructive analytical method capable of determining the biochemical constituents based on molecular vibrations.It does not require sample preparation or pretreatment.However,the use of Raman spectroscopy for in vivo clinical applications will depend on the feasibility of measuring Raman spectra in a relatively short time period(a few seconds).In this work,a fast dispersive-type nearinfrared(NIR)Raman spectroscopy system and a skin Raman probe were developed to facilitate real-time,noninvasive,in vivo human skin measurements.Spectrograph image aberration was corrected by a parabolic-line fiber array,permitting complete CCD vertical binning,thereby yielding a 16-fold improvement in signal-to-noise ratio.Good quality in vivo skin NIR Raman spectra free of interference from fiber fluorescence and silica Raman scattering can be acquired within one second,which greatly facilitates practical noninvasive tissue characterization and clinical diagnosis.Currently,we are conducting a large clinical study of various skin diseases in order to develop Raman spectroscopy into a useful tool for non-invasive skin cancer detection.Intermediate data analysis results are presented.Recently,we have also successfully developed a technically more challenging endoscopic Laser-Raman probe for early lung cancer detection.Preliminary in vivo results from endoscopic lung Raman measurements are discussed.展开更多
文摘表面增强拉曼散射(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。
基金supported by the National Cancer Institute of Canada with funds from the Canadian Cancer Society,the Canadian Institutes of Health Research(Grant No.PPP-79109 and MOP-85011)the Canadian Dermatology Foundation,the VGH&UBC Hospital Foundation In It for Life Fund,and the BC Hydro Employees Community Services Fund.
文摘Raman spectroscopy is a noninvasive,nondestructive analytical method capable of determining the biochemical constituents based on molecular vibrations.It does not require sample preparation or pretreatment.However,the use of Raman spectroscopy for in vivo clinical applications will depend on the feasibility of measuring Raman spectra in a relatively short time period(a few seconds).In this work,a fast dispersive-type nearinfrared(NIR)Raman spectroscopy system and a skin Raman probe were developed to facilitate real-time,noninvasive,in vivo human skin measurements.Spectrograph image aberration was corrected by a parabolic-line fiber array,permitting complete CCD vertical binning,thereby yielding a 16-fold improvement in signal-to-noise ratio.Good quality in vivo skin NIR Raman spectra free of interference from fiber fluorescence and silica Raman scattering can be acquired within one second,which greatly facilitates practical noninvasive tissue characterization and clinical diagnosis.Currently,we are conducting a large clinical study of various skin diseases in order to develop Raman spectroscopy into a useful tool for non-invasive skin cancer detection.Intermediate data analysis results are presented.Recently,we have also successfully developed a technically more challenging endoscopic Laser-Raman probe for early lung cancer detection.Preliminary in vivo results from endoscopic lung Raman measurements are discussed.
