Terahertz Microfluidic Metamaterial Biosensor for Sensitive Detection of Small-Volume Liquid Samples

Metamaterial assisted terahertz (THz) label-free bio-sensing has promising applications. However, the sensitive THz detection of highly absorptive liquid samples remains challenging. Here, we present a novel multi-microfluidic-channel metamaterial biosensor (MMCMMB) for highly sensitive THz sensing of small volume liquid samples. The multi-channels are set mostly in the strong electric field enhancement area of the metamaterial, which significantly decreases the liquid amount and enhances interaction between the sensing targets and the THz wave (thus increasing the sensitivity). The sensing results of isopropyl alcohol (IPA)-water mixtures and bovine serum albumin (BSA) solutions based on the bow-tie array metamaterial with multi-channels demonstrate the effectiveness of this proposed design and the great potential in THz bio-sensing. This design has the advantages of being highly sensitive, label-free, cost-effective, easy to operate and only needing a tiny liquid volume. Thus our device provides a robust route for metamaterial assisted THz label-free bio-sensing of liquid-based substances.