| Surface Plasmon Polaritons(SPPs)are electromagnetic waves that occur at interfaces with different dielectric constants.Because of its characteristics of short wavelength,near field enhancement and surface localization,it has been widely used in high sensitivity sensor design.For example,the design of integrated nano-optical sensors,high-resolution microscopes,high-sensitivity integrated fine platforms in biology and medicine,etc.With the de,velopment of micro-nanofabrication technology,more and more methods are used to fabricate surface plasmon polariton devices.The components based on SPR principle are widely concerned and studied by researchers.At present,many of the sensors based on SPR principle are designed and fabricated by top-down lithography technology on flat substrate,which is costly,time-consuming and complicated.On this basis,we propose a method to fabricate centimeter-scale plasma nanostructure sensors with large area and low cost.Large area of micro-nano pattern structure makes Angle-sensitive exploration possible.Based on the ultra-thin alumina template,a centimeter-level,high sensitivity,low cost and high efficiency sensing platform was fabricated by nano-transfer method.Two angular-dependent resonance modes of the plasma nanodisk structure were observed at non-zero incident angles.The relationship between the volume sensitivity and the surface sensitivity and the incident angle of the two modes is studied systematically.The formant shift sensitivity of functionalized plasma nanostructures during specific binding of biological proteins was monitored in real time at different incident angles.It was found that the specific unlabeled detection limit of the nanodisk biosensor could reach 1.8nM at the incident angle of 10 degrees,which has surpassed the commercial prism surface plasmon sensor.By integrating nanostructures into optical fibers,the fiber-optic plasma nanostructure sensor has good integration,portability and remote control and measurement.However,the technology of integrating nanostructures into tiny optical fiber probes is inherently costly,time-consuming and low yield.In the second chapter of this paper,we use nanosphere lithography technology to develop a nanoporous multi-mode optical fiber probe sensor with low processing cost and short process.Multimode optical fibers have the characteristics of large tip area and large numerical aperture,which not only reduces the processing difficulty and the cost of incident light source,but also facilitates system integration.The volumetric sensitivity and surface sensitivity of nanoporous fiber optic sensors are investigated.The volumetric sensitivity of nanoporous fiber optic sensors can reach 432 nm/RIU.In addition,we also explored and demonstrated the practical application of the miniaturized and portable optical fiber sensing platform for real-time monitoring of protein specific binding.The results show that the sensor fabricated by this method is expected to be a new choice for biosensor system. |
