The invention discloses a terahertz metasurface
biosensor which is modified by a single-stranded
DNA (deoxyribonucleic acid)
nucleic acid aptamer and is used for specifically detecting a
tumor necrosis factor-alpha. Under the
simulation condition, the surface of the
biosensor is covered with a layer of
analyte with the thickness of 20 microns, and when the
refractive index of the
analyte is changed from n = 1 to n = 2, the theoretical sensitivity of the metasurface
biosensor can reach 124.71 GHz / RIU. In an experiment, the metasurface is prepared on a
copper-plated
polyethylene glycol terephthalate sheet by using photoetching and
chemical corrosion processes. Then, according to the characteristic that the
nucleic acid aptamer is specifically combined with the
tumor necrosis factor-alpha, the
nucleic acid aptamer is modified on the surface of the sensor, so that the super-surface biological immunosensor is prepared, the concentration detection of the
tumor necrosis factor-alpha is realized, the
detection limit reaches 0.1 ng / ml, and the detection sensitivity can reach 13.9 GHz / 1g (ng / ml). Besides,
ovalbumin and
whey protein with the same concentration are compared and detected, and the result shows that only the tumor
necrosis factor-alpha can be obviously distinguished, so that the sensor has a
specific detection function. The terahertz metasurface immunosensor provided by the invention realizes the
specific detection of the tumor
necrosis factor-alpha. The work can be used for biomarker detection and early diagnosis of diseases.