Mechanism Analysis And Application Of LSPR-based Sensing

Noble metal nanoparticles show unique optical properties-LSPR(local surface plasmon resonance),Which are characterized by strong light absorption and scattering The LSPR spectroscopy depends on the size,shape,composition and the medium surrounding the nanoparticles.And the LSPR spectroscopy of noble metal nanoparticles is sensitive to the changes of surrounding medium,which enables the nanoparticles to serve as plasmonic nano sensors.In this paper the sensing performance of nanoparticles is studied.The main research work are as follows:(1)The influence of the surrounding medium on NPs' sensing performance is investigated by employing the Mie theory in absorbing medium.The results show that the sensing performance of NPs decrease with the increase of the imaginary part of the complex refractive index of the surrounding medium.And when the imaginary part is larger than a certain value,the NPs are not suitable for sensing.In addition,the application of particles in gas detection is also introduced.(2)The sensing performance of single nanoparticle is investigated by employing the finite difference time domain(FDTD)software.The results show that the shorter the NP is in the incident direction of the incident light or the longer the NP is in the polarization direction of the incident light,the better the NP'S sensing performance is.When the "effective radius" is between 20 and 60nm,the larger NP exhibits higher RI sensitivity but lower FOM.And the Ag NP exhibits the best sensing performance,while the Cu NP exhibits the worst sensing performance among the Au,Ag,Cu NPs.(3)The sensing performance of nanoarrays is investigated by employing the finite difference time domain(FDTD)software,The results of nanoarrays show that,when particle spacing is large,the RI sensitivity of nanoarrays is large,the RI sensitivity of nanoarrays decreases first and then increases as particle spacing decreases,the FOM of nanoarrays exhibits the similar trend.