Extreme sensitive metasensor for targeted biomarkers identification using colloidal nanoparticles-integrated plasmonic unit cells

Abstract

Engineered terahertz (THz) plasmonic metamaterials have emerged as promising platforms for quick infection diagnosis, cost-effective and real-time pharmacology applications owing to their non-destructive and harmless interaction with biological tissues in both and assays. As a recent member of THz metamaterials family, toroidal metamaterials have been demonstrated to be supporting high-quality sharp resonance modes. Here we introduce a THz metasensor based on a plasmonic surface consisting of metamolecules that support ultra-narrow toroidal resonances excited by the incident radiation and demonstrate detection of an ultralow concertation targeted biomarker. The toroidal plasmonic metasurface was designed and optimized through extensive numerical studies and fabricated by standard microfabrication techniques. The surface then functionalized by immobilizing the antibody for virus-envelope proteins (ZIKV-EPs) for selective sensing. We sensed and quantified the ZIKV-EP in the assays by measuring the spectral shifts of the toroidal resonances while varying the concentration. In an improved protocol, we introduced gold nanoparticles (GNPs) decorated with the same antibodies onto the metamolecules and monitored the resonance shifts for the same concentrations. Our studies verified that the presence of GNPs enhances capturing of biomarker molecules in the surrounding medium of the metamaterial. By measuring the shift of the toroidal dipolar momentum (up to Δ~0.35 cm) for different concentrations of the biomarker proteins, we analyzed the sensitivity, repeatability, and limit of detection (LoD) of the proposed toroidal THz metasensor. The results show that up to 100-fold sensitivity enhancement can be obtained by utilizing plasmonic nanoparticles-integrated toroidal metamolecules in comparison to analogous devices. This approach allows for detection of low molecular-weight biomolecules (≈13 kDa) in diluted solutions using toroidal THz plasmonic unit cells.

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

“…In the previous studies, the analyte is usually located in the whole area of the MM and the volume of the analyte is large [5][6][7][8][9][10][11][12][13][14][15][16][20][21][22][23][24][25][26][27]. If we don't consider the required sample volume, the resonance frequency shift per unit refractive index change in our study (72 GHz/RIU for the multichannel design, 223 GHz/RIU for the one big channel design) is comparable to previous studies (such as, 40 GHz/RIU [13], 220 GHz/RIU [20], 305 GHz/RIU [21]).…”

Experimental Observation of Toroidal Dipole Modes in All‐Dielectric Metasurfaces

“…Nevertheless, the position of the hotspots and their shape correspond completely to those found for the intra‐cluster and inter‐cluster polar toroidal dipole mode excitations. The maximum of the electric field is outside of the disks being located either in the center of the cluster or on the periphery of the cluster , which is important from the viewpoint of potential applications in nonlinear optics and sensorics . The results for the Design ② completely coincide with those of the Design ① and therefore are omitted here.…”

Regenerated amplification of terahertz spoof surface plasmon radiation

“…Terahertz (THz) wave spectrum locates between the microwave and far infrared regions and becomes more and more attractive for various applications, including high-data-rate communication, bio-medicine imaging, immunosensing, security inspection, sensitivity-enhanced nuclear magnetic resonance (NMR), and so on [1][2][3][4][5][6][7][8][9]. Room-temperature efficient THz sources play key roles in developing THz technologies and applications.…”