Nguyen Duy-Khiem, Jang Chang-Hyun
Department of Chemistry, Gachon University, Seongnam-daero 1342, Sujeong-gu, Seongnam-si 13120, Korea.
Micromachines (Basel). 2021 Dec 8;12(12):1526. doi: 10.3390/mi12121526.
Here, we designed a simple, rapid, and ultrasensitive colorimetric aptasensor for detecting anatoxin-a (ATX-a). The sensor employs a DNA aptamer as the sensing element and gold nanoparticles (AuNPs) as probes. Adsorption of the aptamer onto the AuNP surface can protect AuNPs from aggregation in NaCl solution, thus maintaining their dispersion state. In the presence of ATX-a, the specific binding of the aptamer with ATX-a results in a conformational change in the aptamer, which facilitates AuNP aggregation and, consequently, a color change of AuNPs from red to blue in NaCl solution. This color variation is directly associated with ATX-a concentration and can be easily measured using a UV/Vis spectrophotometer. The absorbance variation is linearly proportional to ATX-a concentration across the concentration range of 10 pM to 200 nM, with a detection limit of 4.45 pM and high selectivity against other interferents. This strategy was successfully applied to the detection of ATX-a in lake water samples. Thus, the present aptasensor is a promising alternative method for the rapid detection of ATX-a in the environment.
在此，我们设计了一种简单、快速且超灵敏的比色适体传感器用于检测类毒素-a（ATX-a）。该传感器采用DNA适体作为传感元件，金纳米颗粒（AuNPs）作为探针。适体吸附到AuNP表面可保护AuNPs在NaCl溶液中不聚集，从而保持其分散状态。在存在ATX-a的情况下，适体与ATX-a的特异性结合导致适体构象改变，这促进了AuNP聚集，进而使NaCl溶液中的AuNPs颜色从红色变为蓝色。这种颜色变化与ATX-a浓度直接相关，并且可以使用紫外/可见分光光度计轻松测量。在10 pM至200 nM的浓度范围内，吸光度变化与ATX-a浓度呈线性比例关系，检测限为4.45 pM，对其他干扰物具有高选择性。该策略已成功应用于湖水样品中ATX-a的检测。因此，本适体传感器是环境中快速检测ATX-a的一种有前景的替代方法。
