A love wave biosensor using Aptamer sensitive layer

A love-wave biosensor has been designed by coupling aptamers to the Au-surface of sensor chip. Aptamers are artificial nucleic acid ligands that can be obtained in the process of SELEX. Aptamers have advantages over antibodies, such as high affinity, specificity, and stability. As Love waves´ acoustic energy is confined to a thin near-surface region of substrate by guiding layer, Love wave sensors obtain low propagation loss and high sensitivity. As a result, love wave biosensors using Aptamer sensitive layer combining both the advantages stand out in analytical and diagnostic assays. Here, Love-wave sensors are designed as delay-line structure, with a nano-gold sensing area located between the input and output IDTs. For lower threshold detection limit, the substrate utilizes ST-90°X quartz, and EWC/SPUDT is used to reduce transducers´ bidirectional loss. The aptamer probe is immobilized by biotin-avidin system (BAS). Depending on the mass multiplied effect of nano-gold particles and biotin-avidin system, the Love wave biosensor can be used for Arbin detection. As for 1 μg/Mℓ Arbin, the system detection is 6.71KHz, which is almost 2 times higher than BSA (BSA concentration is 1.5 mg/Mℓ). The experimental results show that love-wave biosensor can achieve a comparable sensitivity combining with aptamer sensitive layer.