We review the recent biomedical detection developments of scanning near-field optical microscopy(SNOM),focusing on scattering-type SNOM,atomic force microscope-based infrared spectroscopy,peak force infrared microscop...We review the recent biomedical detection developments of scanning near-field optical microscopy(SNOM),focusing on scattering-type SNOM,atomic force microscope-based infrared spectroscopy,peak force infrared microscopy,and photo-induced force microscopy,which have the advantages of label-free,noninvasive,and specific spectral recognition.Considering the high water content of biological samples and the strong absorption of water by infrared waves,we divide the relevant research on these techniques into two categories:one based on a nonliquid environment and the other based on a liquid environment.In the nonliquid environment,the chemical composition and structural information of biomedical samples can be obtained with nanometer resolution.In the liquid environment,these techniques can be used to monitor the dynamic chemical reaction process and track the process of chemical composition and structural change of single molecules,which is conducive to exploring the development mechanism of physiological processes.We elaborate their experimental challenges,technical means,and actual cases for three microbiomedical samples(including biomacromolecules,cells,and tissues).We also discuss the prospects and challenges for their development.Our work lays a foundation for the rational design and efficient use of near-field optical microscopy to explore the characteristics of microscopic biology.展开更多
We investigate the optical properties of nanostructures of antimony sulfide(Sb2S3),a direct-bandgap semiconductor material that has recently sparked considerable interest as a thin film solar cell absorber.Fabrication...We investigate the optical properties of nanostructures of antimony sulfide(Sb2S3),a direct-bandgap semiconductor material that has recently sparked considerable interest as a thin film solar cell absorber.Fabrication from a nanoparticle ink solution and two-and three-dimensional nanostructuring with pattern sizes down to 50 nm have recently been demonstrated.Insight into the yet unknown nanoscopic optical properties of these nanostructures is highly desired for their future applications in nanophotonics.We implement a spectrally broadband scattering-type near-field optical spectroscopy technique to study individual Sb2S3 nanodots with a 20-nm spatial resolution,covering the range from 700 to 900 nm.We show that in this below-bandgap range,the Sb2S3 nanostructures act as high-refractive-index,low-loss waveguides with mode profiles close to those of idealized cylindrical waveguides,despite a considerable structural disorder.In combination with their high above-bandgap absorption,this makes them promising candidates for applications as dielectric metamaterials,specifically for ultrafast photoswitching.展开更多
基金supported by the National Key Research and Development Program(Grant No.2022YFA1404004)the Key Domestic Scientific and Technological Cooperation Projects in Shanghai(Grant No.21015800200).
文摘We review the recent biomedical detection developments of scanning near-field optical microscopy(SNOM),focusing on scattering-type SNOM,atomic force microscope-based infrared spectroscopy,peak force infrared microscopy,and photo-induced force microscopy,which have the advantages of label-free,noninvasive,and specific spectral recognition.Considering the high water content of biological samples and the strong absorption of water by infrared waves,we divide the relevant research on these techniques into two categories:one based on a nonliquid environment and the other based on a liquid environment.In the nonliquid environment,the chemical composition and structural information of biomedical samples can be obtained with nanometer resolution.In the liquid environment,these techniques can be used to monitor the dynamic chemical reaction process and track the process of chemical composition and structural change of single molecules,which is conducive to exploring the development mechanism of physiological processes.We elaborate their experimental challenges,technical means,and actual cases for three microbiomedical samples(including biomacromolecules,cells,and tissues).We also discuss the prospects and challenges for their development.Our work lays a foundation for the rational design and efficient use of near-field optical microscopy to explore the characteristics of microscopic biology.
基金funding by the Deutsche Forschungsgemeinschaft(SPP1391,SPP1839,GRK1885)the Niedersachsisches Ministerium für Wissenschaft und Kultur(LGRK,Nano-Energieforschung)+2 种基金the Korea Foundation for International Cooperation of Science and Technology(K20815000003)the German-Israeli Foundation(1256)financial support by the China Scholarship Council(CSC 201404910464)
文摘We investigate the optical properties of nanostructures of antimony sulfide(Sb2S3),a direct-bandgap semiconductor material that has recently sparked considerable interest as a thin film solar cell absorber.Fabrication from a nanoparticle ink solution and two-and three-dimensional nanostructuring with pattern sizes down to 50 nm have recently been demonstrated.Insight into the yet unknown nanoscopic optical properties of these nanostructures is highly desired for their future applications in nanophotonics.We implement a spectrally broadband scattering-type near-field optical spectroscopy technique to study individual Sb2S3 nanodots with a 20-nm spatial resolution,covering the range from 700 to 900 nm.We show that in this below-bandgap range,the Sb2S3 nanostructures act as high-refractive-index,low-loss waveguides with mode profiles close to those of idealized cylindrical waveguides,despite a considerable structural disorder.In combination with their high above-bandgap absorption,this makes them promising candidates for applications as dielectric metamaterials,specifically for ultrafast photoswitching.
