Fig. 1. (a) Schematic diagram of optofluidic sensing system; (b) Top view of the array structure

Fig. 2. (a) Simulated zero-order transmission spectrum of the metasurface at  n=1.450 (inset is the electric  field distribution in the two resonance modes); (b) Simulated transmission spectra at different  refractive indices

Fig. 3. (a) Flowchart for metasurface fabrication of silicon nanostructure arrays; (b) Flowchart of PDMS injection molding process; (c) Physical diagram of optofluidic sensor

Fig. 4. (a) Schematic diagram of the experimental test system; (b) Experimental test optical platform

Fig. 5. (a) Experimental transmission spectra of different refractive index solutions; (b) Linear fit of resonance wavelength and refractive index variation; (c) Experimental Q and FOM values for EQ-qBIC; (d) Experimental Q and FOM values for MD-qBIC