Flexible terahertz metamaterial biosensor for label-free sensing of serum tumor marker modified on a non-metal area

Terahertz (THz) metamaterials for rapid label-free sensing show application potential for the detection of cancer biomarkers. A novel flexible THz metamaterial biosensor based on a low refraction index parylene-C substrate is proposed. The biomarkers are modified on non-metal areas by a three-step modification method that simplifies the modification steps and improves the modified effectivity. Simulation results for non-metal modification illustrate that a bulk refractive index sensitivity of 325 GHz/RIU is achieved, which is larger than that obtained for the traditional metal modification (147 GHz/RIU). Meanwhile, several fluorescence experiments proved the uniform modification effect and selective adsorption capacity of the non-metal modification method. The concentration of the carcinoembryonic antigen (CEA) biomarkers for breast cancer patients tested using this THz biosensor is found to be consistent with results obtained from traditional clinical tests. The limit of detection reaches 2.97 ng/mL. These findings demonstrate that the flexible THz metamaterial biosensor can be extensively used for the rapid detection of cancer biomarkers in the future. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

A novel flexible THz metamaterial biosensor based on a low refraction index substrate is proposed for rapid label-free detection of cancer biomarkers. The biomarkers are modified using a non-metal modification method, achieving high refractive index sensitivity and uniform modification effect. The biosensor shows consistent results with traditional clinical tests.