基于脱氧核酶的水中铀酰离子光纤倏逝波生物传感检测技术研究

为了满足铀的高通量快速筛查及环境突发事件快速检测的需要,本研究利用脱氧核酶的特异性催化反应,结合本课题组自主研制开发的倏逝波光纤生物传感器,通过设计两步法的反应策略,即"均相反应,固相杂交"的检测方案,建立了光纤倏逝波生物传感检测铀酰离子的新型技术方法.结果发现,该方法对于5~100 nmol·L~(-1)内的铀酰离子具有良好的线性检测区间,检测限低至0.5 nmol·L~(-1),整个检测过程仅需16 min即可完成,铅和汞等10种金属离子对于本检测方法无明显干扰,表现出了对铀酰离子的良好选择性.传感光纤可重复使用100次以上,不会有信号的明显衰减,可有效降低检测成本.对丹江口水库水进行的实际水样加标回收实验结果显示,丹江口水库实际水样的加标回收率为91.6%~94.6%.本研究可为利用生物传感器法检测环境水体中的铀酰离子提供技术支撑.

DNAzyme-based optical fiber evanescent wave biosensor for detection of uranyl ion in water samples

To meet the demand of high-throughput and rapid screening and detection of UO₂²⁺ in unexpected environmental pollution accidents, a sensitive and rapid method was successfully established. We integrated the UO₂²⁺ specific cleavage reaction catalyzed by a DNAzyme with the all-fiber evanescent wave biosensor platform developed by our research group. The sensitive and fast detection of UO₂²⁺ was achieved by adopting a two-step strategy that consists of a cleavage reaction in solution and a subsequent hybridization on the fiber surface. The method showed good linear dynamic range (from 5 to 100 nmol·L^-1), high sensitivity (the limit of detection at 0.5 nmol·L^-1), and rapid response (16 min). No obvious interference was observed from ten other metal ions including lead and mercury, suggesting the excellent selectivity. The fiber was reused more than 100 times without significant signal attenuation. The sensor worked well for the detection of uranyl ion spiked in the water collected from Danjiangkou reservoir with the recovery of 91.6%~94.6%.