Abstract: A chiral metamaterial absorber modeled after the yin-yang symbol comprising: a top yin-yang shaped Au nanoparticles (YNPs); a PMMA layer; an Au backreflector; and a bottom glass layer. In alternative embodiments, provided are devices acting as sensors for detecting a nucleotide such as a cDNA and/or a protein such as a protein from a pathogen such as a bacteria or a virus, wherein the cDNA or protein can be derived from a Coronavirus, for example, a SARS CoV-2 or COVID-19 virus. In alternative embodiments, devices acting as sensors as provided herein can also be used to detect any protein for diagnostic or therapeutic purposes, wherein the protein can be derived from a blood or plasma sample, or a tissue sample, for example, a biopsy, from an individual in need thereof, for example, a human or an animal.