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

Abstract

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. IndexTerms-Terahertz spectroscopy, biomedical spectroscopy, metamaterial, microfluidic.

Large Near-Field Enhancement in Terahertz Antennas by Using Hyperbolic Metamaterials with Hole Arrays

“…Results show that E y is negligible, |E x | 2 in the gap of the conventional antenna is greatly enhanced to 1 × 10 4 , whereas |E z | 2 is very weak (only 12). In other words, E x dominates the near field, consistent with the literature [11]. However, for the proposed antenna structure, both the electric field components are greatly enhanced: |E x | 2 = 2.4 × 10 4 , |E z | 2 = 1.5 × 10 4 .…”

“…Since commercially available high-power terahertz sources are expensive, it is crucial to enhance the localized field intensity, thus enabling strong light-matter interactions in diverse exciting applications such as detection [6], sensing [7], absorption [8], spectral filtering [9], and emission [10], and significantly improving the performance of the corresponding devices. For example, by confining most electric energy to a small region filled with microfluid, the sensitivity of a terahertz sensor can be greatly improved [11].…”

“…By efficiently coupling and confining the free-space terahertz radiations to a small (usually subwavelength) region, a terahertz antenna can greatly enhance the localized near fields. Therefore, terahertz antennas have been widely used in a diverse range of applications including biosensing [11][12][13][14][15][16] and detection [17,18]. An important figure of merit for these terahertz antennas is the near-field enhancement, which is defined as the ratio of the near-field electric field intensity and the electric field intensity of the incidence [19].…”

THz Detection of Biomolecules in Aqueous Environments—Status and Perspectives for Analysis Under Physiological Conditions and Clinical use

“…The globular proteins human serum albumin (HSA) [91] and bovine serum albumin (BSA) [35,50,81,85,139,157,183,190], the enzyme lysozyme [21,85,157,177,182], the prosthetic group biotin [10], the oxygen-carrying muscle protein myoglobin [23,112,157,189], the biotin-binding protein avidin [192], the antifreeze protein DAFP-1 [106], the photoactive yellow protein [49], alanine-rich peptides [36], the peptide amyloid beta [58] and the artificial peptide sequences P-NIPAAm [116,147] have been investigated with traditional THz techniques. Absorption spectra and optical constants have been recorded and determined considering the requirement for reduced interaction between THz fields and absorbing aqueous media [10,21,35,49,50,81,91,112,117].…”

Reusable, Non-Invasive, and Ultrafast Radio Frequency Biosensor Based on Optimized Integrated Passive Device Fabrication Process for Quantitative Detection of Glucose Levels

“…With regard to optical biosensors, it needs a long settling time for detection and is highly susceptible to change the test results for ambient light [33][34][35][36][37][38][39][40][41]. Recently, a biosensor based on radio frequency (RF) techniques has attracted enormous attention and is regarded as a promising and competitive candidate for implementing third-generation glucose biosensors [42][43][44][45][46][47]. Compared to other types of biosensors, RF biosensors offer the following advantages: first, they are different from the electrochemical biosensors, which are subject to the constraints of the use environment and performance degradation with service time.…”