Laboratory of Process Engineering and Environment, Faculty of Sciences and Techniques, Hassan II University of Casablanca, P.A. 146, Mohammedia, Morocco.
Laboratory of Process Engineering and Environment, Faculty of Sciences and Techniques, Hassan II University of Casablanca, P.A. 146, Mohammedia, Morocco.
Talanta. 2021 Aug 1;230:122346. doi: 10.1016/j.talanta.2021.122346. Epub 2021 Mar 23.
Rapid, sensitive, and portable analytical methods for on-site inspection of food fraud are now an urgent requirement to ensure food quality and satisfy the ethnic considerations of consumers. Hence, for the first time, a colorimetric smartphone-based immunoassay was developed for the on-site detection of pork adulteration in meat. In detail, the immunoassay was based on a competitive strategy in which immobilized standard porcine IgG competed with the target porcine IgG extracted in a single step from meat samples. The parameters involved in each step of the immunoassay conception and the digital colorimetric detection were carefully investigated and optimized. Using polystyrene microplates as ready-to-use stable and portable immunoplatforms, TMB as chromogenic substrate, smartphone as signal readout, and Image J software for image processing; the developed immunoassay was able to detect as low as 0.01% of pork in meat mixtures in a total assay time of 30 min. The selectivity of the immunoassay was evaluated for different meat species, and it was shown to selectively respond only to pork. Furthermore, excellent stability of the prepared immunological platform was demonstrated under extreme temperature conditions (50 °C), which confirms its high portability potential for in situ quantification of pork, while being relatively cost effective and non-laborious. The developed method also provides great precision (RSD < 6%) and accuracy (relative error< 6%). Given the universal use of smartphones as portable and affordable devices, such format of immunoassay could be a promising approach for rapid and sensitive real-time monitoring of food fraud.
快速、灵敏、便携的现场食品欺诈分析方法是确保食品质量和满足消费者民族需求的迫切要求。因此，首次开发了一种基于智能手机的比色免疫分析方法，用于现场检测肉类中的猪肉掺假。具体而言，该免疫分析基于竞争策略，其中固定化标准猪 IgG 与从肉样中一步提取的目标猪 IgG 竞争。仔细研究和优化了免疫分析构思和数字比色检测的各个步骤中的参数。使用聚苯乙烯微孔板作为即用型稳定且便携的免疫平台、TMB 作为显色底物、智能手机作为信号读出器以及 Image J 软件进行图像处理；所开发的免疫分析能够在 30 分钟的总分析时间内检测到肉混合物中低至 0.01%的猪肉。评估了免疫分析对不同肉类物种的选择性，结果表明它仅选择性地响应猪肉。此外，还证明了制备的免疫平台在极端温度条件（50°C）下具有出色的稳定性，这证实了其用于现场定量检测猪肉的高便携性潜力，同时相对具有成本效益且不费力。所开发的方法还提供了出色的精密度（RSD<6%）和准确性（相对误差<6%）。鉴于智能手机作为便携且经济实惠的设备被普遍使用，这种免疫分析格式可能是快速灵敏的实时监测食品欺诈的有前途的方法。
