Research On Chiral Molecular Sensing Based On Chiral Nano-optical Structure Of Magnetic Oxide Thin Films

Chiral molecules are important components of the human body,such as amino acids,enzymes,sugars,etc.To treat human diseases,specific chiral drugs are required.On the contrary,chiral drugs will endanger human health,so the detection of chiral drug molecules becomes very important.The traditional detection methods are mass spectrometry and chromatography,and there are problems such as complex test procedures,time-consuming and high cost.The detection method based on chiral optical response has the advantages of simple operation,fast detection speed and low cost,and has attracted widespread attention.However,because the chiral molecular size is much smaller than the wavelength of the incident light,the chiral optical response of the molecule is weak,which limits its practical application.With the development of micronanofabrication technology,the use of superchiral field of chiral nanostructures to enhance molecular chiral signals has become a hot research direction in the field of chiral sensing.However,the chiral signal of chiral nanostructures has the risk of masking the signal of chiral molecules,which is an urgent problem to be solved in this field.In view of the above research background,this paper mainly carried out research on chiral molecular sensing based on achiral nanostructures and magnetically tunable chiral nanostructures.The specific research content of the paper is as follows1.Aiming at the problem of strong chiral signal of chiral nanostructures,an achiral gold rod structure was designed and prepared to eliminate the influence of structural chirality,and further construct localized plasmon resonance and incident light coupling to generate superchiral near-field,which enhances chiral molecular transmission.sense signal.Through the chiral molecular sensing experiment test,the far-field signal after sensing with the gold rod structure can reach about ±1200 mdeg,and compared with the CD signal of the chiral molecule itself,the detection signal has achieved two orders of magnitude enhancement.2.Further,we use the chiral structure with a stronger superchiral field for chiral molecular sensing,by introducing magnetic functional materials,and using the magnetic field to dynamically eliminate the chiral signal of the structure.We designed a "卍"-shaped chiral nanostructure,and theoretically proved that the superchiral field of the structure reaches 60.Compared with the previously reported method to eliminate chirality by subtracting two enantiomeric structures,this method has the advantages of simple nanofabrication and complete structural chirality elimination,which is expected to improve the sensitivity of chiral molecular sensing.