Pan Jiafeng, Zeng Ying, Wang Yuyan, Ren Xiaoya, Yang Fei, Chen Junhua
Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.
Anal Chem. 2025 Feb 4;97(4):2556-2565. doi: 10.1021/acs.analchem.4c06655. Epub 2025 Jan 17.
A sensitive fluorescence biosensor was developed for microcystin-LR (MC-LR) detection using H1, H2, and H3 DNA probes as sensing elements. The aptamer in H1 can recognize the target. H2 was labeled with FAM and BHQ. The MC-LR and H1 binding will activate the H2 and H3 self-assemblies through toehold-mediated strand displacement. In the formed products (MC-LR/H1/nH2/nH3), FAM and BHQ will be separated and a high FAM fluorescence signal can be observed for the MC-LR assay. The biosensor is sensitive with a detection limit of 53 fM. We further constructed several logic circuits (AND-AND cascaded circuit, feedforward circuit, and resource allocation circuit) using MC-LR, MC-LA, and MC-YR as the three inputs. The numbers 0 and 1 are used to code the input and output signals. The AND-AND cascade circuit can produce a high output signal only in the (111) input combination. In the feedforward circuit, MC-LR and MC-LA can activate the logic circuit to produce high signals, and MC-YR will inhibit the self-assembly and execute the negative feedforward operation. Through the rational design of the DNA probe hybridizations on four different magnetic beads (MBs), the resource allocation circuit can achieve an intelligent allocation of input information. Our proposed fluorescence biosensor can not only provide a sensitive platform for microcystin detection but also serve as a smart and intelligent logic system for microcystin sensing.
利用H1、H2和H3 DNA探针作为传感元件，开发了一种用于检测微囊藻毒素-LR（MC-LR）的灵敏荧光生物传感器。H1中的适体可以识别靶标。H2用FAM和BHQ标记。MC-LR与H1的结合将通过链置换介导的链置换激活H2和H3的自组装。在形成的产物（MC-LR/H1/nH2/nH3）中，FAM和BHQ将分离，并且可以观察到用于MC-LR检测的高FAM荧光信号。该生物传感器灵敏，检测限为53 fM。我们进一步以MC-LR、MC-LA和MC-YR作为三个输入构建了几个逻辑电路（与-与级联电路、前馈电路和资源分配电路）。数字0和1用于编码输入和输出信号。与-与级联电路仅在（111）输入组合中产生高输出信号。在前馈电路中，MC-LR和MC-LA可以激活逻辑电路以产生高信号，而MC-YR将抑制自组装并执行负前馈操作。通过在四种不同磁珠（MBs）上合理设计DNA探针杂交，资源分配电路可以实现输入信息的智能分配。我们提出的荧光生物传感器不仅可以为微囊藻毒素检测提供一个灵敏的平台，还可以作为一个用于微囊藻毒素传感的智能逻辑系统。
