Carbon dots as new nanomaterials, have been widely used in rapid detection because of their nondestructive, real-time detection characteristics. Improving the sensitivity and selectivity of the method in complex real samples is new challenge and requirement for sensing technology. Here, we report an ultrasensitive fluorescence immunoassay (FIA) for trace diethyl phthalate (DEP) using red carbon dots@SiO₂ (R-CDs@SiO₂) as tags. SiO₂ as a nanocarrier can effectively improve the bio-functionalization and utilization rate of carbon dots. Moreover, several R-CDs embedded in SiO₂ nanospheres can magnify the fluorescence signal and improve sensitivity. R-CDs@SiO₂ conjugate anti-DEP antibody (Ab) as fluorescent immunosensor, which can specifically recognize DEP. Under optimization conditions, the detection limit (LOD) of this FIA was calculated as 0.0011 ng/mL. In addition, the recoveries of this established FIA ranged from 96.8 to 108.5%, showing satisfactory accuracy. Compared with GC-MS/MS (LOD µg/mL), the sensitivity of the FIA was significantly improved. As a result, the FIA developed using R-CDs@SiO₂ as tags has a high potential for determining trace DEP.

碳点作为新型纳米材料，以其无损、实时的检测特性，被广泛应用于快速检测领域。提高该方法在复杂真实样品中的灵敏度和选择性是传感技术面临的新挑战和新要求。在这里，我们报告了使用红碳点@SiO ₂ (R-CDs@SiO ₂ ) 作为标记的痕量邻苯二甲酸二乙酯 (DEP) 的超灵敏荧光免疫测定 (FIA)。SiO ₂作为纳米载体可以有效提高碳点的生物功能化和利用率。_{此外，嵌入SiO 2}纳米球中的多个R-CD可以放大荧光信号并提高灵敏度。R-CDs@SiO ₂结合抗 DEP 抗体 (Ab) 作为荧光免疫传感器，可以特异性识别 DEP。在优化条件下，该 FIA 的检测限 (LOD) 计算为 0.0011 ng/mL。此外，此已建立的 FIA 的回收率介于 96.8 至 108.5% 之间，显示出令人满意的准确性。与 GC-MS/MS（LOD µg/mL）相比，FIA 的灵敏度显着提高。因此，使用 R-CDs@SiO ₂作为标签开发的 FIA 具有确定痕量 DEP 的高潜力。