Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, And Beijing Laboratory for Food Quality and Safety, Beijing, 100193, People's Republic of China.
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, People's Republic of China.
Anal Chim Acta. 2020 Mar 15;1102:91-98. doi: 10.1016/j.aca.2019.12.037. Epub 2019 Dec 18.
Immunoassays such as the enzyme-linked immunosorbent assay (ELISA) are utilized extensively for detecting protein biomarkers and small molecules in healthcare, environmental monitoring, and food analysis. Unfortunately, the current strategies for immunoassays often require sophisticated apparatus such as a microplate reader, which might not be available in resource-limited areas. To mitigate this problem, we designed a compact smartphone based-device and a multicolor response immunosensor. First, we designed a compact and cost-effective 3D-printed attachment, where a light-emitting diode was used as a light excitation source and a smartphone captured the fluorescent emission signals. Second, by combining quantum dots hybrid and chemical redox reaction, multiple color responses were displayed in the presence of the analyte at different concentrations. Third, solutions with distinct tonality could be readily distinguished by the naked eye and they were suitable for quantitative analysis using the hue-saturation-lightness color space based on a smartphone application. The versatility of the proposed sensing system was demonstrated by implementing an indirect competitive ELISA for analyzing trace drug residues in foodstuffs. The multicolor response of this sensing strategy allows us to visually quantify drug residues in foodstuffs. Moreover, the smartphone-based immunosensor can assess the exact concentration of the analyte by using a self-designed mobile application. The proposed assay provides a highly sensitive performance that the limit of detection was 0.37 ng/mL by visual detection and 0.057 ng/mL using the compact device. Due to its advantages in terms of portability, straightforward visual detection, high sensitivity, and cost effectiveness, the proposed immunosensor has great potential for applications in areas without access to laboratories or expensive infrastructure.
免疫分析，如酶联免疫吸附测定（ELISA），广泛用于检测医疗保健、环境监测和食品分析中的蛋白质生物标志物和小分子。然而，当前的免疫分析策略通常需要复杂的仪器，如微板读数器，而在资源有限的地区可能无法获得这些仪器。为了解决这个问题，我们设计了一种基于智能手机的紧凑型设备和一种多色响应免疫传感器。首先，我们设计了一种紧凑且经济高效的 3D 打印附件，其中使用发光二极管作为光激发源，智能手机捕获荧光发射信号。其次，通过结合量子点杂交和化学氧化还原反应，在不同浓度的分析物存在下显示出多种颜色响应。第三，不同色调的溶液可以通过肉眼轻松区分，并且可以使用基于智能手机应用程序的色调-饱和度-亮度颜色空间进行定量分析。通过实施用于分析食品中痕量药物残留的间接竞争 ELISA，证明了所提出的传感系统的多功能性。该传感策略的多色响应允许我们直观地定量食物中的药物残留。此外，基于智能手机的免疫传感器可以通过使用自行设计的移动应用程序来评估分析物的确切浓度。该测定法提供了高度灵敏的性能，通过视觉检测的检出限为 0.37ng/mL，使用紧凑型设备的检出限为 0.057ng/mL。由于其便携性、直观的视觉检测、高灵敏度和成本效益优势，所提出的免疫传感器在没有实验室或昂贵基础设施的地区具有很大的应用潜力。
