Improved biomolecular detection sensitivity based on concave metamaterial structure

•We propose a concave metallic copper monolayer metamaterial structure to achieve improved detection sensitivity.•In order to analyze the substance under test more intuitively and in multiple dimensions, we extract the frequency shift data of different polarization angles to construct a multi-dimensional hexagonal radar map.•We fabricated the designed metamaterial structures using photolithography and tested the bovine serum albumin biomolecule. Using a continuous wave terahertz spectroscopy measurement system, we tested the transmission properties of two concentrations of bovine serum albumin.