Chirality is ubiquitous in natural world.Although with similar physical and chemical properties,chiral enantiomers could play different roles in biochemical processes.Discrimination of chiral enantiomers is extremely ...Chirality is ubiquitous in natural world.Although with similar physical and chemical properties,chiral enantiomers could play different roles in biochemical processes.Discrimination of chiral enantiomers is extremely important in biochemical,analytical chemistry,and pharmaceutical industries.Conventional chiroptical spectroscopic methods are disadvantageous at a limited detection sensitivity because of the weak signals of natural chiral molecules.Recently,superchiral fields were proposed to effectively enhance the interaction between light and molecules,allowing for ultrasensitive chiral detection.Intensive theoretical and experimental works have been devoted to generation of superchiral fields based on artificial nanostructures and their application in ultrasensitive chiral sensing.In this review,we present a survey on these works.We begin with the introduction of chiral properties of electromagnetic fields.Then,the optical chirality enhancement and ultrasensitive chiral detection based on chiral and achiral nanostructures are discussed respectively.Finally,we give a short summary and a perspective for the future ultrasensitive chiral sensing.展开更多
The chiral feature of an optical field can be evaluated by the parameter of g-factor enhancement,which is helpful to enhance chiroptic signals from a chiral dipole.In this work,the superchiral spot has been theoretica...The chiral feature of an optical field can be evaluated by the parameter of g-factor enhancement,which is helpful to enhance chiroptic signals from a chiral dipole.In this work,the superchiral spot has been theoretically proposed in metal-insulator-metal waveguides.The g-factor enhancement of the superchiral spot can be enhanced by 67-fold more than that of circularly polarized light,and the spot is confined in the deep wavelength scale along each spatial dimension.Moreover,the position of the superchiral spot can be tuned by manipulating the incident field.The tunable superchiral spot may find applications in chiral imaging and sensing.展开更多
Circularly polarized light(CPL)is an inherently chiral entity and is regarded as one of the possible deterministic signals that led to the evolution of homochirality in earth.Thus,CPL as an external physical field has...Circularly polarized light(CPL)is an inherently chiral entity and is regarded as one of the possible deterministic signals that led to the evolution of homochirality in earth.Thus,CPL as an external physical field has been widely used in a technique known as absolute asymmetric synthesis,because a product enriched in one enantiomer is formed from racemic precursor molecules without the intervention of a chiral catalyst.In this review,we retrospect the historical research of CPL-induced absolute asymmetric synthesis,including chiral organic molecules,helical polymers,supramolecular assemblies,noble metal nanostructures.However,based on these results,we concluded that the chiral photon-matter interaction is very faint due to the arrangement of molecular bonds giving rise to chiral features,is over a smaller distance than the helical pitch of CPL,leading extremely small enantiomeric excess for product.Therefore,we highlight the recently emerged technology called superchiral field,in which the superchiral far-field and near-field could enhance the dissymmetry of optical field and near-field,respectively.In sum,we hope this review could bring some enlightenment to researchers and further improve the enantioselectivity of CPL-induced absolute asymmetric synthesis.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91850205 and 11904021).
文摘Chirality is ubiquitous in natural world.Although with similar physical and chemical properties,chiral enantiomers could play different roles in biochemical processes.Discrimination of chiral enantiomers is extremely important in biochemical,analytical chemistry,and pharmaceutical industries.Conventional chiroptical spectroscopic methods are disadvantageous at a limited detection sensitivity because of the weak signals of natural chiral molecules.Recently,superchiral fields were proposed to effectively enhance the interaction between light and molecules,allowing for ultrasensitive chiral detection.Intensive theoretical and experimental works have been devoted to generation of superchiral fields based on artificial nanostructures and their application in ultrasensitive chiral sensing.In this review,we present a survey on these works.We begin with the introduction of chiral properties of electromagnetic fields.Then,the optical chirality enhancement and ultrasensitive chiral detection based on chiral and achiral nanostructures are discussed respectively.Finally,we give a short summary and a perspective for the future ultrasensitive chiral sensing.
基金supported by the National Natural Science Foundation of China(Nos.62075132 and 92050202)Natural Science Foundation of Shanghai(No.22ZR1443100).
文摘The chiral feature of an optical field can be evaluated by the parameter of g-factor enhancement,which is helpful to enhance chiroptic signals from a chiral dipole.In this work,the superchiral spot has been theoretically proposed in metal-insulator-metal waveguides.The g-factor enhancement of the superchiral spot can be enhanced by 67-fold more than that of circularly polarized light,and the spot is confined in the deep wavelength scale along each spatial dimension.Moreover,the position of the superchiral spot can be tuned by manipulating the incident field.The tunable superchiral spot may find applications in chiral imaging and sensing.
基金the support of Academic promotion program of Shandong First Medical University(No.2019LJ003)。
文摘Circularly polarized light(CPL)is an inherently chiral entity and is regarded as one of the possible deterministic signals that led to the evolution of homochirality in earth.Thus,CPL as an external physical field has been widely used in a technique known as absolute asymmetric synthesis,because a product enriched in one enantiomer is formed from racemic precursor molecules without the intervention of a chiral catalyst.In this review,we retrospect the historical research of CPL-induced absolute asymmetric synthesis,including chiral organic molecules,helical polymers,supramolecular assemblies,noble metal nanostructures.However,based on these results,we concluded that the chiral photon-matter interaction is very faint due to the arrangement of molecular bonds giving rise to chiral features,is over a smaller distance than the helical pitch of CPL,leading extremely small enantiomeric excess for product.Therefore,we highlight the recently emerged technology called superchiral field,in which the superchiral far-field and near-field could enhance the dissymmetry of optical field and near-field,respectively.In sum,we hope this review could bring some enlightenment to researchers and further improve the enantioselectivity of CPL-induced absolute asymmetric synthesis.
