Acetylcholinesterase Sensing Based On Dielectric Nano-antennas

With the rapid development of dielectric nano-antennas,radiation devices in the light bands have been gradually invented.Dielectric antenna biosensor is becoming a new hotspot in the research and application of biomolecule detection.In the dielectric nano-antenna devices,the design of Huygens element structure is very important,its structural parameters directly affect the quality factor of the transmission or reflection spectrum,which will affect the sensitivity of biomolecule detection.Biological platforms based on the dielectric nano-antennas generally have the characteristics of miniaturization and high-quality factor resonance signal.Compared with commonly used detection methods for acetylcholinesterase(AChE),the dielectric nano-antenna detection method is more direct,efficient and safer.In this paper,a silicon disk dielectric antenna for the detection of AChE is first studied here.Using the simulation software FDTD of time-domain difference method to analyze the influence of the structure's size,period and background refractive index to the backward light.This sample is made by electron beam lithography technology and the optical system of spectrum measurement is set up.The electrical resonance position is used to calibrate the refractive index of the surface environment,and the sensitivity reaches 222 nm/RIU.The minimum detectable concentration of AChE is 0.1 mg/ml by wet measurement method.The chemical bond coupling method is introduced to monitor the AChE concentration changing process.And there is no need to mark the detection substance,by modifying the surface of the antenna structure and fixing the AChE antibodies on the surface.Finally,the specific monitoring process of AChE concentration is achieved,the minimum detectable concentration is 0.01 mg/ml which is ten orders of magnitude higher than that of the wet method.High sensitivity detection of AChE concentration is an important method for water pollution control and treatment,the research content will provide technical support for water pollution prevention and control.