ABSTRACT

Carcinoembryonic antigen (CEA) is usually utilised as a reliable diagnostic and predictive marker of gastric cancer (GC). Herein, a target-responsive, label-free aptamer ‘signal-on’ fluorescent biosensing system was developed based on the synthesis of DNA-templated quantum dots via one-pot route and interactions with graphene oxide. CEA triggered aptamer-DNA hairpins hybridisation to release DNA to hybridise with DNA-CdTe QDs on GO and led to the fluorescence recovery of system with a ‘signal-on’ status. The fluorescence intensity was proportionate to CEA concentration, and highly sensitive sensing platform for detecting CEA was achieved with a wide linear range (5–250 ng/mL) and a low detection limit (1.17 ng/mL). This sensing strategy, the targeted detection of aptamer for CEA, provided a new direction in the detection of protein and construction of fluorescence biosensors.

摘要

癌胚抗原 (CEA) 通常被用作胃癌 (GC) 的可靠诊断和预测标志物。在此，基于通过一锅法合成以 DNA 为模板的量子点以及与氧化石墨烯的相互作用，开发了一种目标响应、无标记的适体“信号开启”荧光生物传感系统。CEA 触发适体-DNA 发夹杂交以释放 DNA 以与 GO 上的 DNA-CdTe QD 杂交，并导致具有“信号开启”状态的系统的荧光恢复。荧光强度与 CEA 浓度成正比，实现了用于检测 CEA 的高灵敏度传感平台，具有宽线性范围 (5–250 ng/mL) 和低检测限 (1.17 ng/mL)。这种传感策略，CEA适体的靶向检测，