Key Laboratory of Analytical Science for Food Safety and Biology (MOE & Fujian Province), Department of Chemistry , Fuzhou University , Fuzhou 350108 , People's Republic of China.
Anal Chem. 2019 Aug 6;91(15):10049-10055. doi: 10.1021/acs.analchem.9b01958. Epub 2019 Jul 11.
A ratiometric photoelectrochemical (PEC) sensing strategy was proposed for monitoring of carcinoembryonic antigen (CEA) based on a homemade 3D printing device with dual-working photoelectrodes (PE and PE), coupling λ-exonuclease (λ-Exo)-assisted recycling amplification with CdS quantum dots. Gold nanoparticles-functionalized ZnO nanorods were utilized as PEC substrate for generating initial photocurrent and immobilizing DNA probe. Upon incubation of target with DNA trigger/CEA aptamer-modified magnetic bead (tri/apt-MB), DNA trigger dissociated from magnetic bead and then hybridized with capture probe (cp) on PE or opened hairpin probe (hp) on PE to form double-stranded DNA (dsDNA). The exonuclease could recognize and cleave two newly generated dsDNA, leading to the release of trigger. The free trigger strand continued to hybridize with the remaining cp/hp, which were cleaved by λ-Exo, and then trigger was released again and restarted next recycle with the λ-Exo. After digestion of λ-Exo, the number of capture probes on PE was reduced, and many short DNA fragments were produced on PE, thereby resulting in the decreasing CdS QDs on PE and the increasing CdS QDs on PE. As a result, it was observed that the ratio value of photocurrents (PE/PE) significantly decreased with the increasing CEA. Under optimum conditions, the sensing method showed a good linear relationship toward CEA within the dynamic range of 0.02-10 ng mL and a detection limit of 6.0 pg mL. Moreover, the ratiometric PEC sensor exhibited good reproducibility, satisfying stability, and remarkable anti-interference performance, which suggests its promising application prospect to detect target CEA.
提出了一种基于自制 3D 打印装置的比率型光电流化学（PEC）传感策略，用于监测癌胚抗原（CEA），该装置具有双工作光电极（PE 和 PE），结合了λ-核酸外切酶（λ-Exo）辅助的循环放大与 CdS 量子点。金纳米粒子功能化的氧化锌纳米棒被用作 PEC 基底，用于产生初始光电流和固定 DNA 探针。将目标物与 DNA 触发/CEA 适体修饰的磁性珠（tri/apt-MB）孵育后，DNA 触发从磁性珠上解离，并与 PE 上的捕获探针（cp）或 PE 上的开环发夹探针（hp）杂交形成双链 DNA（dsDNA）。核酸外切酶可以识别并切割两个新生成的 dsDNA，导致触发物的释放。游离的触发物链继续与剩余的 cp/hp 杂交，这些探针被 λ-Exo 切割，然后触发物再次释放并与 λ-Exo 重新开始下一轮循环。λ-Exo 消化后，PE 上的捕获探针数量减少，PE 上产生了许多短的 DNA 片段，导致 PE 上的 CdS QDs 减少，PE 上的 CdS QDs 增加。结果发现，随着 CEA 的增加，光电流的比值（PE/PE）显著降低。在最佳条件下，该传感方法在 0.02-10 ng mL 的动态范围内对 CEA 表现出良好的线性关系，检测限为 6.0 pg mL。此外，比率型 PEC 传感器表现出良好的重现性、令人满意的稳定性和显著的抗干扰性能，表明其在检测目标 CEA 方面具有广阔的应用前景。
