Multimodal detection method based on the peroxidase-like activity and fluorescent properties of cerium-doped carbon dots for sensitive detection of phosphatidylethanolamine in food.

Abstract

Phosphatidylethanolamine (PE) is an important indicator for evaluating the nutritional value and quality of food. In this study, a multimodal detection method (UV/smartphone/fluorescence/paper-based sensing platform) was developed for PE detection in food on the basis of the peroxidase-like activity and fluorescence properties of cerium-doped carbon dots (Ce-CDs). The prepared CDs generated singlet oxygen (1O2) through the Russell mechanism, which oxidized 3,3',5,5'-tetramethylbenzidine (TMB) to produce ox-TMB. The addition of PE changed the surface charge of Ce-CDs, enhancing their affinity with TMB and causing the solution to turn bluer. In addition, these CDs exhibited excellent optical properties and fluorescence stability. In fluorescence detection, PE significantly quenched the fluorescence of the reaction system through an inner filter effect mechanism. Furthermore, the designed paper-based sensing platform provided a novel tool for on-site high-throughput detection of PE. The signal values of Ce-CDs in various detection modes exhibit a good linear relationship with PE concentrations ranging from 0.1 to 1000 μg/mL, with a lowest detection limit of 0.023 μg/mL. More importantly, all methods successfully realized the detection of PE in real food samples and obtained satisfactory results. This study not only developed multiple detection methods based on the same material but also ensured the accuracy of the results through cross-validation between the different methods.