CRISPR/Cas12a trans-cleavage cascading dual-template exponential amplification reaction for electrochemiluminescent detection of 17β-estradiol in milk

17(3-Estradiol (E2) is a common environmental estrogen that can interfere with the endocrine systems of humans and animals, and poses a carcinogenic risk even at picomolar concentrations. In this study, a functionalized Ru (bpy)32+-embedded metal-organic framework (ZnRuMOF) is synthesized, in which Ru(bpy)32+ served as an electrochemiluminescence (ECL) indicator and the porous structure of ZnRuMOF acts as a nanoreactor to enhance the ECL signal. Based on this, we developed an E2 detection method combining a highly specific CRISPR-Cas12a system and dual-template exponential amplification. This method utilizes the trans-cleavage activity of CRISPR-Cas12a to control a light switch, achieving precise and ultra-sensitive detection of E2. The sensing platform demonstrates excellent performance in detecting E2 concentrations ranging from 1 fg mL- 1 to 150 ng mL-1, with a detection limit of 0.27 fg mL-1 (S/N = 3). This study provides a reliable approach for diagnosing and treating diseases related to E2, aiming to protect environmental quality and human health.