Characteristics of pure Love mode SAW sensor with graphene interdigital transducer for biosensing applications

The characteristics of Love wave biosensors are systematically investigated. The results show that sensors with combination of a ZnO guiding layer and 90ST or 90AT Quartz substrates exhibit purer Love modes than those with the SiO2 guiding layer. The corresponding maxi- mum sensitivities are −10.9069 and −11.641m2/kg, respectively, which are nearly two times higher than those of SiO2 layer. The ZnO/90ST Quartz Love wave sensor exhibits the largest K2 of 0.3022 and achieves 0 ppm/oC of TCF at hZnO/λ = 0.0216. The sensor employing the Graphene IDT further improves the sensitivity by nearly one order of magnitude.