Magnetic surface molecularly imprinted polymers for efficient selective recognition and targeted separation of daidzein

Daidzein, a naturally occurring source of estrogenic isoflavones, holds significant promise for various applications in food and drug development. Therefore, to realize efficient and precise daidzein separation, we synthesized a magnetic surface molecularly imprinted polymer (Daidzein/SMIPs) via free radical-initiated polymerization via magnetic surface molecular imprinting technology. The adsorption capacity of the Daidzein/SMIPs for daidzein at an initial concentration of 300 µg·mL −1 reached 18.44 mg·g −1 within 20 min at 298 K. Even after nine adsorption-desorption cycles, the adsorption capacity remained high (81.42% of the initial adsorption capacity). Furthermore, the Daidzein/SMIPs exhibited exceptional selectivity for daidzein, with an imprinting factor of 1.83 and selection coefficients ( K ) of 1.94, 2.43, 2.63, and 1.66 for structurally similar competing molecules such as naringin, quercetin, diosmetin, and alizarin, respectively. In practical applications, isolating daidzein from real daidzein tablets using the Daidzein/SMIPs resulted in high recoveries of 88.09 to 98.12% with excellent precision (relative standard deviation of 1.51–1.02%). Therefore, the constructed Daidzein/SMIPs feature immense potential for targeted daidzein isolation applications.