The content of biothiols in cells is highly associated with the occurrence and development of several diseases.However,due to their active chemical properties,thiol-contained molecules are normally volatile during the...The content of biothiols in cells is highly associated with the occurrence and development of several diseases.However,due to their active chemical properties,thiol-contained molecules are normally volatile during the detection process,rendering precise analysis of intracellular biothiols challenging.In this study,5,5’-dithiobis-(2-nitrobenzoic acid)(DTNB)is covalently modified on the surface of gold nanorods(AuNRs),constructing sensing substrates for in situ Raman imaging analysis of biothiols in cells.Au NRs are able to serve as ideal surface-enhanced Raman scattering substrates,and thus Raman signals of DTNB are greatly amplified by AuNRs.Meanwhile,the disulfide bond of DTNB can be broken by thiols,thereby releasing part of DTNB from the surface of AuNRs.As a result,three kinds of main biothiols are sensitively quantified with DTNB-modified AuNRs according to the variation of Raman signals,and DTNB-modified Au NRs exhibit far better analytical performance than a commercial probe.In addition,the sensing substrates can be readily delivered to cytoplasm with the transmembrane of Au NRs,and are capable of responding to biothiols in cells.Notably,the Raman approach is established by the breaking of chemical bonds rather than the aggregation of substrates,which is more inclined to analyze intracellular biothiols with a desirable spatial resolution.Therefore,fluctuation of biothiols in glioma cells is evidently observed via Raman imaging.Overall,this work provides an alternative strategy for designing Raman sensors to visualize active molecules in cells.展开更多
Optical metamaterials can concentrate light interaction with quantum objects. In this paper, into extremely tiny volumes to enhance their a cylindrical microcavity based on the Au-dielectric-Au sandwiched structure i...Optical metamaterials can concentrate light interaction with quantum objects. In this paper, into extremely tiny volumes to enhance their a cylindrical microcavity based on the Au-dielectric-Au sandwiched structure is proposed. Numerical study shows that the cylindrical microcavity has the strong ability of localizing light and confining 10^3- - 10^4-fold enhancement of the electromagnetic energy density, which contains the most energy of the incoming light. The enhancement factor of energy density G inside the cavity shows the regularities as the change in the thickness of the dielectric slab, dielectric constant, and the radius of gold disk. At the normal incidence of electromagnetic radiation, the obtained reflection spectra operate in the range from 4.8 μm to 6μm and with the absorption efficiency C （C=1-Rmin）, which can reach 99% by optimizing the structure＇s geometry parameters, and the dielectric constant. Due to the symmetry of the cylindrical microcavities, this structure is insensitive to the polarization of the incident wave. The proposed optical metamaterials will have potential applications in the surface enhanced spectroscopy, new plasmonic detectors, bio-sensing, solar cells, etc.展开更多
基金supported by the National Natural Science Foundation of China(22234005,21974070,22222407,22176099)the Natural Science Foundation of Jiangsu Province(BK20192008)the State Key Laboratory of Analytical Chemistry for Life Science(SKLACLS2220)。
文摘The content of biothiols in cells is highly associated with the occurrence and development of several diseases.However,due to their active chemical properties,thiol-contained molecules are normally volatile during the detection process,rendering precise analysis of intracellular biothiols challenging.In this study,5,5’-dithiobis-(2-nitrobenzoic acid)(DTNB)is covalently modified on the surface of gold nanorods(AuNRs),constructing sensing substrates for in situ Raman imaging analysis of biothiols in cells.Au NRs are able to serve as ideal surface-enhanced Raman scattering substrates,and thus Raman signals of DTNB are greatly amplified by AuNRs.Meanwhile,the disulfide bond of DTNB can be broken by thiols,thereby releasing part of DTNB from the surface of AuNRs.As a result,three kinds of main biothiols are sensitively quantified with DTNB-modified AuNRs according to the variation of Raman signals,and DTNB-modified Au NRs exhibit far better analytical performance than a commercial probe.In addition,the sensing substrates can be readily delivered to cytoplasm with the transmembrane of Au NRs,and are capable of responding to biothiols in cells.Notably,the Raman approach is established by the breaking of chemical bonds rather than the aggregation of substrates,which is more inclined to analyze intracellular biothiols with a desirable spatial resolution.Therefore,fluctuation of biothiols in glioma cells is evidently observed via Raman imaging.Overall,this work provides an alternative strategy for designing Raman sensors to visualize active molecules in cells.
文摘Optical metamaterials can concentrate light interaction with quantum objects. In this paper, into extremely tiny volumes to enhance their a cylindrical microcavity based on the Au-dielectric-Au sandwiched structure is proposed. Numerical study shows that the cylindrical microcavity has the strong ability of localizing light and confining 10^3- - 10^4-fold enhancement of the electromagnetic energy density, which contains the most energy of the incoming light. The enhancement factor of energy density G inside the cavity shows the regularities as the change in the thickness of the dielectric slab, dielectric constant, and the radius of gold disk. At the normal incidence of electromagnetic radiation, the obtained reflection spectra operate in the range from 4.8 μm to 6μm and with the absorption efficiency C （C=1-Rmin）, which can reach 99% by optimizing the structure＇s geometry parameters, and the dielectric constant. Due to the symmetry of the cylindrical microcavities, this structure is insensitive to the polarization of the incident wave. The proposed optical metamaterials will have potential applications in the surface enhanced spectroscopy, new plasmonic detectors, bio-sensing, solar cells, etc.
