Fig. 1. Manufacture and characterization of the HDOMM. (a) Manufacturing process: (i) an EIT-like metasurface sample was prepared; (ii) a metal halide perovskite [CH3NH3PbI3 (MAPbI3)] was spin-coated on the EIT-like metasurface sample; (iii) the PI film was spin-coated on MAPbI3; (iv) graphene was transferred onto the PI film; (v) the trilayer graphene was patterned into a fishing net structure with round holes; (vi) sericin was qualitatively sensed. (b) Three optical microscope images of the different samples. (c) Unit cell of the EIT-like metasurface. The corresponding parameters are P=200  μm, l=170  μm, w=20  μm, a=130  μm, b=60  μm, c=40  μm, d=15  μme=10  μm, m=36  μm. (d) Raman spectrum of graphene. The inset is a sample of the EIT-like metasurface with the patterned graphene and MAPbI3 film. (e) X-ray diffraction (XRD) pattern of the perovskite films. The inset is an SEM image of MAPbI3.

Fig. 2. Performance and mechanism of the EIT-like metasurface. (a) Experimental and simulated transmission spectra. (b) Simulated transmission spectra under different conductivities. (c) Simulated electric field distributions at 0.65 THz. (d) Surface current distributions at 0.65 THz. (e)–(h) Simulated electric field distributions under different conductivities.

Fig. 3. Sensing performance of the HDOMM biosensor based on amplitude. (a)–(c) Experimental transmission spectra. (d)–(f) Corresponding theoretical fitted transmission spectra from (a)–(c). (g)–(i) Fitting parameters γ1 and γ2 as functions of sericin concentration. (j)–(l) Sensing mechanisms.

Fig. 4. Sensing performance of the HDOMM biosensor based on phase. (a)–(c) Experimental phase spectra for the HDOMM at sericin concentrations from 780 pg/mL to 1.25 μg/mL. (d) Role of perovskite in phase-based sensing.

Table 1. Δγ/γ for Different Sericin Concentrations

Table 2. Comparison with Previous Works^a