Molecular Editing-Biolayer Interferometry Technique for Sensitive, Rapid, and High-Throughput Detection of Multiple Steroid Environmental Estrogens

The simultaneous detection of multiple steroid environmental estrogens (SEEs, E1, E2, EE2 for instance) is critical for comprehensively assessing environmental risks and safeguarding public health. In this study, we developed a novel molecular editing-biolayer interferometry (BLI) technology for the sensitive, rapid, and high-throughput detection of multiple SEEs in various water samples. An oligonucleotide sequence editing technique was employed to precisely tailor the molecular structures of aptamers P1 and P2. Aptamer P1 was immobilized on the BLI biosensor, while aptamer P2 was premixed with water samples containing SEEs. Results from spectroscopic experiments, isothermal titration calorimetry, and molecular docking simulation revealed significant improvements in the binding interactions between the edited aptamers and SEEs. The formation of a stable ternary structure between P1 and the P2-SEEs complex further amplified changes in the optical thickness of the molecular layer on the BLI biosensor, endowing this molecular editing-BLI technology with superior sensitivity and selectivity for detecting low molecular weight SEEs. This method effectively detected low concentrations of individual and mixed SEEs within the 0.001-1 nM range, achieving a remarkable 7 orders of magnitude increase in recognition efficiency compared to the original aptamer-SEEs interactions. Without the need for sample pretreatment, this multichannel sensing method simultaneously detected SEEs concentrations in 8 water samples within just 7 min. This study provides a powerful tool for the effective monitoring of SEEs in the environment, contributing to the protection of human health and the ecological environment.