*2.2. Preparation of Bi-MIPs, Bi-NIPs, Si-MIPs and Si-NIPs*

The Bi-MIPs were synthesized by the precipitation polymerization method, using chrysin as template molecule, MAA and AM as function monomers, EGDMA as crosslinker and AIBN as initiator. Chrysin (0.3 mmol), MAA (2.4 mmol) and AM (0.4 mmol) were dissolved in 50 mL of methanol in a 250 mL three-necked round-bottomed flask. The function monomers (MAA (2.4 mmol) and AM (0.4 mmol)) interacted with the template molecule (chrysin) through intermolecular force to form a stable "pre-polymerization" complex. Then, the 50 mL of mixture solution of EGDMA (9.6 mmol), AIBN (0.1043 g) and methanol was added and dispersed under ultrasound. The mixture was heated followed by mechanical agitation (50 rpm) and heat-polymerized at 65 ◦C for 12 h. The synthesis process is shown in Figure 1. The Bi-MIPs were collected through vacuum filtration, and the unreacted monomers were removed by methanol: acetic acid (9:1, *v*/*v*) extraction for 24 h and methanol extraction for 12 h. The Bi-MIPs were dried under a vacuum at 50 ◦C for 12 h. The binary functional monomers molecularly non-imprinted polymer (Bi-NIP) microspheres were synthesized using the same procedure as the Bi-MIPs, but without the chrysin (template molecules). The Si-MIPs were synthesized following the same procedure without adding the AM. The single functional monomer molecularly non-imprinted polymers (Si-NIPs) were synthesized following the same procedure without adding the AM and chrysin.

**Figure 1.** The scheme for preparing the Bi-MIPs (R is -O-CH2-CH2-O-).
