This paper reports a quantitative and sensitive one-step point-of-care testing (POCT) chip built on a perfluorinated substrate patterned with polydopamine microspots array. The capture antibody was covalently immobilized on the polydopamine microspots, while the fluorescently labelled detection antibody was physically adsorbed on the perfluorinated surface. The POCT chip allowed one-step sandwich immunoassay and was able to directly detect the analytes from the whole blood without sample preprocessing. By further taking advantages of the strong fluorescence quenching ability of the polydopamine, the blocking-free substrate was able to achieve similar performance in detecting and quantifying the protein biomarkers as the substrate with the blocking treatment. The blocking-free strategy not only made the fabrication of the chip simple and convenient, but also improved the chip's sensitivity for biomarker quantification. Finally, we demonstrated that the self-contained POCT platform maintained the performance for one-step immunoassay even after long-term storage. With the POCT platform, we are one step closer to a sample-in-answer-out diagnostic system.

本文报道了一种定量和灵敏的一步检验点（POCT）芯片，该芯片建立在以聚多巴胺微点阵列为图案的全氟底物上。捕获抗体共价固定在聚多巴胺微点上，而荧光标记的检测抗体则物理吸附在全氟化表面上。POCT芯片可进行一步式夹心免疫分析，无需样品预处理即可直接从全血中检测分析物。通过进一步利用聚多巴胺的强荧光猝灭能力，无封闭底物能够在检测和定量蛋白质生物标志物方面获得与封闭处理相似的性能。无阻塞策略不仅使芯片的制造简单方便，而且还提高了芯片对生物标志物定量的敏感性。最终，我们证明了自包含的POCT平台即使在长期保存后仍可保持一步免疫分析的性能。借助POCT平台，我们离抽样输入诊断系统仅一步之遥。