State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China.
Analyst. 2011 Sep 21;136(18):3649-55. doi: 10.1039/c1an15384f. Epub 2011 Jul 28.
Due to the dangerous nature of anthrax, the development of a cost-effective, sensitive and field-portable sensor for the anthrax biomarker--calcium dipicolinate (CaDPA)--is of exceptional significance for both military and civilian use. Herein, a flexible polymer-film-based ratiometric sensor for detecting CaDPA was demonstrated. A reference dye and a probe ligand were covalently immobilized onto the film surface through a highly selective and efficient "click chemistry" reaction. The reference dye, whose fluorescence intensity does not change with varying amounts of CaDPA, offers a non-interfering internal calibration. The ethylenediaminetetraacetic acid (EDTA)-based ligand binds with Eu(III) and serves as the probe. In the absence of CaDPA, the film sensor exhibited almost no red fluorescence because the Eu(III) ions themselves give no emission without sensitization by CaDPA owing to the small molar absorption coefficients of Eu(III) ions. The presence of CaDPA induces a significantly enhanced emission intensity of the sensor, and thereby enables the film as a ratiometric sensor for CaDPA. This sensor can selectively detect CaDPA in water with a detection limit of 100 nM. Moreover, this sensor exhibited strong anti-interfering capability, it can not only be used in milieus that contain various amino acids and some biologically-abundant cations, but can also be usable in some biological fluids such as urine and serum. This test-paper-like film sensor is suitable for portable field analysis and needs no extra protective measures during transport due to its flexibility, and it can easily be separated from the analyte solution after the detection.
由于炭疽的危险性，开发一种经济有效、灵敏且适用于现场的炭疽生物标志物——钙二吡咯羧酸（CaDPA）传感器，对于军事和民用都具有特殊意义。本文展示了一种基于柔性聚合物薄膜的比率型传感器，用于检测 CaDPA。通过高度选择性和高效的“点击化学”反应，将参考染料和探针配体共价固定在薄膜表面。参考染料的荧光强度不会随 CaDPA 量的变化而变化，提供了非干扰的内部校准。基于乙二胺四乙酸（EDTA）的配体与 Eu(III)结合，作为探针。在没有 CaDPA 的情况下，由于 Eu(III)离子本身没有敏化剂时没有发射，因为 Eu(III)离子的摩尔吸收系数很小，因此薄膜传感器几乎没有红色荧光。CaDPA 的存在会显著增强传感器的发射强度，从而使该薄膜成为 CaDPA 的比率型传感器。该传感器可以选择性地检测水中的 CaDPA，检测限为 100 nM。此外，该传感器表现出很强的抗干扰能力，不仅可以在含有各种氨基酸和一些生物丰富阳离子的环境中使用，还可以在尿液和血清等一些生物流体中使用。这种试纸状的薄膜传感器适用于便携式现场分析，由于其柔韧性，在运输过程中不需要额外的保护措施，并且在检测后可以很容易地与分析物溶液分离。
