Early diagnosis of a progressive cancer disease is currently limited due to lack of adequate point-of-care (PoC) diagnostic tools. PoC diagnosis enables detecting early signs of a disease and pave way to disease prevention. Here, we developed an immuno-optomagnetic quantum dots based PoC assay for early detection of a cancer biomarker, human epidermal growth factor receptor-2 (hErbB2) protein in serum. This assay utilizes immuno-optomagnetic quantum dots (MQDs-Ab2) nanoarchitectures with unique orientation comprised of core CdSe/CdS/ZnS QD nanocrystals surrounded by layers of magnetic Fe₃O₄ nanoparticles (MNPs) and a bioactivated borofloat PoC-chip (Ab1). The MQDs-Ab2 and the PoC-chips were designed to bind same hErbB2 analyte, but both bind with distinct epitopes. First, free hErbB2 protein from serum was captured by MQDs-Ab2 forming immuno-optomagnetic MQDs-Ab2-hErbB2 complex, which was isolated and presented to bioactivated PoC-chips. The immuno-optomagnetic signal from chips was directly visualized by naked-eye after exposing chips with a UV-torch and the signal was directly measured within 30 min by computing RGB intensities using a smartphone camera and a colorimeter-app. The immuno-optomagnetic QDs based PoC-chip exhibited the detection range of 620 pg mL⁻¹ ∼5 ng mL⁻¹ hErbB2 protein in serum. The MQDs-Ab2 rendered biospecificty, magnetic and optical functionality to PoC detection and provided advantages of speed, sensitivity, portability and low-cost, which is most desired in resource limited settings. The developed PoC chip assay provided an accurate quantitative cancer biomarker detection with high sensitivity and specificity that required no laboratory equipment and is also potentially applicable to the detection of many other biomarkers.

由于缺乏适当的即时诊断（PoC）诊断工具，目前进展性癌症的早期诊断受到限制。PoC诊断可以检测疾病的早期征兆，为预防疾病铺平道路。在这里，我们开发了一种基于免疫光量子点的PoC分析法，用于早期检测血清中的癌症生物标记物，人类表皮生长因子受体2（hErbB2）蛋白。此测定法利用具有独特方向的免疫光量子点（MQDs-Ab2）纳米结构，该结构由被磁性Fe ₃ O ₄层包围的核心CdSe / CdS / ZnS QD纳米晶体组成纳米粒子（MNP）和生物活化的硼浮法PoC芯片（Ab1）。MQDs-Ab2和PoC芯片设计为结合相同的hErbB2分析物，但均结合不同的表位。首先，通过MQDs-Ab2捕获血清中的游离hErbB2蛋白，形成免疫光MQDs-Ab2-hErbB2复合物，将其分离并呈递至生物激活的PoC芯片中。在用紫外线炬暴露芯片后，用肉眼直接观察来自芯片的免疫光信号，并使用智能手机相机和比色计应用程序通过计算RGB强度在30分钟内直接测量该信号。上述免疫光磁量子点基于POC的芯片表现出620的检测范围皮克毫升^-1〜5纳克毫升^-1血清中的hErbB2蛋白。MQDs-Ab2为PoC检测提供了生物特异性，磁性和光学功能，并提供了速度，灵敏度，便携性和低成本的优势，这在资源有限的环境中最为需要。研发的PoC芯片检测技术提供了一种准确的定量癌症生物标志物检测方法，具有高灵敏度和特异性，不需要实验室设备，也可能适用于许多其他生物标志物的检测。