A rapid and low cost photoluminescence (PL) immunosensor for the determination of low concentrations of Ochratoxin A (OTA) has been developed. This immunosensor was based on porous silicon (PSi) and modified by antibodies against OTA (anti-OTA). PSi layer was fabricated by metal-assisted chemical etching (MACE) procedure. Main structural parameters (pore size, layer thickness, morphology and nanograins size) and composition of PSi were investigated by means of X-Ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. PL-spectroscopy of PSi was performed at room temperature and showed a wide emission band centered at 680 ± 20 nm. Protein A was covalently immobilized on the surface of PSi, which in next steps was modified by anti-OTA and BSA in this way a anti-OTA/Protein-A/PSi structure sensitive towards OTA was designed. The anti-OTA/Protein-A/PSi-based immunosensors were tested in a wide range of OTA concentrations from 0.001 upto 100 ng/ml. Interaction of OTA with anti-OTA/Protein-A/PSi surface resulted in the quenching of photoluminescence in comparison to bare PSi. The limit of detection (LOD) and the sensitivity range of anti-OTA/Protein-A/PSi immunosensors were estimated. Association constant and Gibbs free energy for the interaction of anti-OTA/Protein-A/PSi with OTA were calculated and analyzed using the interaction isotherms. Response time of the anti-OTA/Protein-A/PSi-based immunosensor toward OTA was in the range of 500–700 s. These findings are very promising for the development of highly sensitive, and potentially portable immunosensors suitable for fast determination of OTA in food and beverages.

已经开发出一种快速，低成本的光致发光（PL）免疫传感器，用于测定低浓度的ch曲霉毒素A（OTA）。该免疫传感器基于多孔硅（PSi），并通过针对OTA的抗体（anti-OTA）进行了修饰。PSi层是通过金属辅助化学蚀刻（MACE）程序制造的。通过X射线衍射（XRD），扫描电子显微镜（SEM）和拉曼光谱研究了PSi的主要结构参数（孔尺寸，层厚度，形态和纳米颗粒尺寸）和组成。PSi的PL光谱在室温下进行，显示出以680±20 nm为中心的宽发射带。蛋白A共价固定在PSi的表面上，然后通过抗OTA和BSA对其进行修饰，从而设计了一种对OTA敏感的抗OTA /蛋白质-A / PSi结构。在0.001至100 ng / ml的各种OTA浓度下测试了基于抗OTA /蛋白A / PSi的免疫传感器。与裸露的PSi相比，OTA与抗OTA /蛋白质-A / PSi表面的相互作用导致光致发光的猝灭。估计了检测极限（LOD）和抗OTA /蛋白质A / PSi免疫传感器的灵敏度范围。计算和分析了抗OTA /蛋白质-A / PSi与OTA相互作用的缔合常数和吉布斯自由能。基于抗OTA /蛋白质A / PSi的免疫传感器对OTA的响应时间为500-700 s。这些发现对于开发适用于食品和饮料中OTA的快速测定的高灵敏度，潜在便携式免疫传感器非常有前途。