A high-resolution colorimetric immunoassay for tyramine detection based on enzyme-enabled growth of gold nanostar coupled with smartphone readout

• Published in: Food chemistry 2022-12, Vol.396, p.133729-133729, Article 133729
• Main Authors: Luo, Lin, Luo, Shuang-Zi, Jia, Bao-Zhu, Zhang, Wen-Feng, Wang, Hong, Wei, Xiao-Qun, Shen, Yu-Dong, Lei, Hong-Tao, Xu, Zhen-Lin, Yang, Jin-Yi
• Format: Article
• Language: English
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2022.133729

•Monoclonal antibody specific for tyramine was prepared based on a new hapten design.•Alkaline phosphatase enabled the growth of gold nanostars for multicolor generation.•A multicolor colorimetric immunoassay for tyramine was developed.•Smartphone was used for quantitative detection of tyramine. In this work, a specific monoclonal antibody against tyramine was produced based on a new hapten design. Then, we developed a high-resolution multicolor colorimetric immunoassay for tyramine based on this antibody by integrating enzyme-induced multicolor generation with smartphone-assistant signal readout. The multicolor generation is due to the shift of the local surface plasmon resonance band of gold nanostructure controlled by alkaline phosphatase-induced the growth of gold nanostars. Quantitative detection of tyramine was achieved via analyzing the red/blue channel values of assay solution’s image taken by a smartphone with the support of a color recognizer application. The limit of detection of this immunoassay for tyramine detection in beef, pork and yoghurt was 19.7 mg/kg or L. The average recoveries were between 83 % and 103 %., and the results were validated by high performance liquid chromatography to be reliable. Overall, this developed immunoassay provides a promising platform for on-site detection of tyramine.