Terahertz Metamaterial Biosensor with Double Resonant Frequencies for Specific Detection of Early-Stage Hepatocellular Carcinoma

A novel strategy for screening early hepatocellular carcinoma (HCC) using a terahertz (THz) metamaterials (MMs) biosensor modified with the antibody against alpha-fetoprotein (AFP) is proposed. The designed biosensor consists of split-resonant-rings (SRRs) with double resonant frequencies that are optimized using the finite integration time domain (FITD) method and manufactured by a surface micromachining process. The experimental results indicate that the HCC biomarker AFP could be accurately distinguished with a concentration as low as 0.1 ng/mL via analyzing the shifts of double resonant frequencies. Meanwhile, specific detection of AFP-antigen in solution and HCC serum has been achieved through the antigen-antibody specific binding. These results demonstrate the sensitivity and specificity of THz MMs biosensor for molecular detection of trace cancer biomarkers in biochemical sensing. Furthermore, the sensitivity of specific cancer biomarkers can be further improved by optimizing the MM structure and applying the double resonant frequencies. Therefore, this approach may own great potential for special identification of early cancer molecules.