This work reveals the deleterious effect of microcystin-LR (MC-LR) on the conformation of DNA and develops an electrochemical biosensor for detection of MC-LR. The biosensor is prepared by physically immobilizing calf thymus DNA (ctDNA) on gold electrode. In the presence of MC-LR, the conformation change of immobilized ctDNA decreases the electron transfer impedance, thus enhances the amperometric response. The proposed method shows a linear range of 4–512 ng/L and a detection limit of 1.4 ng/L, which is 700-fold lower than the guideline level suggested by the World Health Organization. The detection results are in good agreement with those from the conventional HPLC method. This biosensor possesses good stability against other components in natural water sample, and has been used for detection of MC-LR in local water bodies, indicating its application promise.

这项工作揭示了微囊藻毒素-LR（MC-LR）对DNA构象的有害作用，并开发了一种用于检测MC-LR的电化学生物传感器。通过将小牛胸腺DNA（ctDNA）物理固定在金电极上来制备生物传感器。在存在MC-LR的情况下，固定的ctDNA的构象变化会降低电子传递阻抗，从而增强安培响应。所提出的方法的线性范围为4–512 ng / L，检出限为1.4 ng / L，比世界卫生组织建议的指导水平低700倍。检测结果与常规HPLC方法的检测结果非常吻合。这种生物传感器对天然水样品中的其他成分具有良好的稳定性，并已用于检测当地水体中的MC-LR，