Quantitative fluorescence immunoassay is a vital and convenient method in point-of-care (POC) testing for food safety and clinical healthcare. However, current marking materials, from organic luciferin to quantum dots, still lack the requirement of increasing need for multiple targets of interest because of their too broad emission. Here, a new label material, perovskite nanocrystals (Pe-NCs), with a narrower photoluminescence spectrum is reported, and a sensitive and quantitative immunoassay method named the perovskite nanocrystal fluorescence-linked immunosorbent assay is preliminarily demonstrated. The key point of realizing water-dispersed and stable Pe-NCs was addressed by functionalizing with hydroxyl groups. The fluorescent probes (perovskite antibody) were constructed via electrostatic adsorption with narrow full-width at half-maximum (∼18 nm), laying the foundation for future study of multi-target detection. Both indirect competitive immunity and sandwich immunoassay were successfully demonstrated. This work provides a possible label material for POC tests and may open up a promising avenue of next-generation immunoassay.

定量荧光免疫测定法是用于食品安全和临床保健的即时检验（POC）测试中至关重要且便捷的方法。但是，目前的标记材料，从有机荧光素到量子点，仍然缺乏对多个感兴趣的靶标的需求，因为它们的发射范围太广。在此，报道了一种具有较窄的光致发光光谱的新型标记材料钙钛矿纳米晶体（Pe-NCs），并初步证明了一种灵敏且定量的免疫测定方法，称为钙钛矿纳米晶体荧光连接免疫吸附法。通过用羟基官能化解决了实现水分散且稳定的Pe-NC的关键点。荧光探针（钙钛矿抗体）是通过静电吸附在半最大（〜18 nm）处具有狭窄的全宽度而构建的，为将来的多目标检测研究奠定了基础。成功地证明了间接竞争免疫和三明治免疫测定。这项工作为POC测试提供了可能的标签材料，并可能为下一代免疫测定开辟一条有希望的途径。