The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
Anal Chim Acta. 2023 Sep 15;1274:341586. doi: 10.1016/j.aca.2023.341586. Epub 2023 Jul 4.
Electrochemical aptasensor has been widely studied, while its practical application is limited by the unavoidable variations of aptamer loading densities and low signal amplification efficiency. To overcome these restrictions, an immobilization-free and label-free electrochemical homogeneous aptasensor was constructed for carcinoembryonic antigen (CEA) assay by combining RecJ exonuclease-mediated target cycling strategy and rolling circle amplification technology. In this system, the pre-immobilization of aptamers or other relevant signal elements on the electrode substrate is no longer necessary, thus the electrochemical homogeneous aptasensor shows good versatility on different transducers. Moreover, the whole recognition and signal amplification process are activated instantaneously by a non-professional operation of the solution mixture. This strategy can not only increase the stability (95.1% after 30 days of storage) and reproducibility (2.12% among five independent electrodes), but also further improve the sensitivity (detection limit of fg mL level) due to the free target recognition and dual signal amplification in the homogeneous solution phase. The proposed immobilization-free electrochemical homogeneous aptasensors on different electrode substrates both achieve satisfactory results in actual sample tests, which has the potential for commercial applications and the establishment of other target platforms in the future.
电化学适体传感器得到了广泛的研究，但其实际应用受到适体装载密度不可避免的变化和低信号放大效率的限制。为了克服这些限制，通过结合 RecJ 核酸外切酶介导的靶循环策略和滚环扩增技术，构建了一种无需固定化和标记的电化学均相适体传感器，用于癌胚抗原（CEA）的检测。在该系统中，不再需要将适体或其他相关信号元件预先固定在电极基底上，因此电化学均相适体传感器在不同的换能器上具有良好的通用性。此外，整个识别和信号放大过程通过溶液混合物的非专业操作瞬间激活。该策略不仅可以提高稳定性（储存 30 天后为 95.1%）和重现性（5 个独立电极之间为 2.12%），而且由于在均相溶液相中自由的靶识别和双重信号放大，还可以进一步提高灵敏度（检测限达到 fg mL 水平）。在不同电极基底上构建的免固定化电化学均相适体传感器在实际样品测试中均取得了令人满意的结果，这为未来的商业应用和其他目标平台的建立提供了潜力。
