State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China; Wageningen Food Safety Research, Wageningen University & Research, P.O. Box 230, 6700 AE Wageningen, The Netherlands.
Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China.
J Hazard Mater. 2022 Jun 15;432:128692. doi: 10.1016/j.jhazmat.2022.128692. Epub 2022 Mar 12.
Polydiacetylene (PDA) is very suited for sensitively detecting large biomolecules, and its unique chromatic properties enable visual read-out. However, application to the selective detection of small molecules remains challenging. Here, bifunctional ligands are studied to amplify the color change of PDA for biorecognition of small molecules for the smartphone-based detection of diethylstilbestrol (DES). PDA is decorated with streptavidin (PDA-SA, blue), and biotin-modified DES (bio-DES) is prepared as a bifunctional ligand to couple with PDA-SA and DES antibody. Since multiple bio-DES can bind to a single SA, then multiple SAs on PDA lead to an increased surface coverage of the vesicle. In samples without DES, PDA-SA-bio-DES-DES antibody complexes will form, leading to a color transition (blue to red); this color transition is greatly amplified by antibody-induced aggregation of the complexes. When DES is present, aggregation is inhibited due to competition for the antibody and PDA-SA-bio-DES retains its blue color. A linear relationship (0.4-1250 ng mL) is found between the colorimetric response and the logarithmic DES concentration, with adequate selectivity, accuracy (82.24-118.64%), and precision (below 8.24%). Finally, a paper-based DES PDA biosensor is developed with visual and smartphone-based detection limits of 10 ng mL and 0.85 ng mL in water, respectively.
聚二乙炔（PDA）非常适合灵敏地检测大生物分子，其独特的颜色特性使其能够进行可视化读取。然而，将其应用于小分子的选择性检测仍然具有挑战性。在这里，研究了双功能配体以放大 PDA 的颜色变化，用于小分子的生物识别，从而实现基于智能手机的对己烯雌酚（DES）的检测。PDA 用链霉亲和素（PDA-SA，蓝色）修饰，并且制备生物素修饰的 DES（bio-DES）作为双功能配体与 PDA-SA 和 DES 抗体偶联。由于多个 bio-DES 可以与单个 SA 结合，因此 PDA 上的多个 SA 导致囊泡的表面覆盖率增加。在没有 DES 的样品中，PDA-SA-bio-DES-DES 抗体复合物将形成，导致颜色转变（蓝色变为红色）；这种颜色转变通过复合物的抗体诱导聚集而大大放大。当存在 DES 时，由于抗体和 PDA-SA-bio-DES 的竞争，聚集受到抑制，并且保留其蓝色。发现比色响应与 DES 浓度的对数之间存在线性关系（0.4-1250ngmL），具有足够的选择性、准确性（82.24-118.64%）和精密度（低于 8.24%）。最后，开发了基于纸张的 DES PDA 生物传感器，其在水中的可视化和基于智能手机的检测限分别为 10ngmL 和 0.85ngmL。
