Aptamer cleavage optimization, binding mechanism analysis, and dual-chemiluminescence sensor for microcystin detection

作者：Zhongmei Peng, Xuning Kang, Zhenlin Fan, Jingping Zhang, Yuzhu Song, Jinyang Zhang, Qinqin Han · 发表于：Talanta · 年份：2025 · DOI：10.1016/j.talanta.2025.127948 · 被引用次数：7 · 研究领域：Advanced biosensing and bioanalysis techniques、Advanced Nanomaterials in Catalysis、Molecular Sensors and Ion Detection

This study aimed to develop a high-affinity and highly specific aptamer , microcystins (MCs)-12 using Capture-Systematic Evolution of Ligands by Exponential Enrichment technology based on immobilized libraries. This aptamer simultaneously recognized three conformations of microcystins (MC-LR, MC-RR, and MC-YR). The stem-loop structure of the aptamer sequence MCs-12 was cleaved and optimized by removing the bases step by step. The optimized sequence M-Apt-6, which had an affinity for MCs, was obtained with only 27 bases. In addition, the possible binding sites and mechanisms of M-Apt-6 for MC-LR, MC-RR, and MC-YR were predicted by circular dichroism , molecular docking , and molecular dynamics simulations . A chemiluminescence sensor was developed based on M-Apt-6 to detect MC-LR, MC-RR, and MC-YR in Dianchi Lake water simultaneously. The M-Apt-6 aptamer specifically bound to MCs. The aptamer not bound to MCs was adsorbed on AuNPs to produce a testable chemiluminescent signal in a luminol-AgNO 3 or luminol-H 2 O 2 system. The aggregation of AuNPs induced by the MCs/M-Apt-6 complex catalyzed the luminol-AgNO 3 or luminol-H 2 O 2 chemiluminescence reactions. The results showed a significant linear relationship between chemiluminescence intensity and MCs concentration. The luminol-AgNO 3 and luminol-H 2 O 2 systems showed good linearity for MCs concentration in the range of 0.5–25.0 ng/mL and 0.5–100.0 ng/mL, with the detection limits of 0.22 ng/mL and 0.01 ng/mL, respectively.