Abstract Sensitive on-line detection of Cu2+ in lubricating oil of marine power plant is important for displaying equipment wear status and fault pre-judgment in real time. However, there are few reports on in-situ, portable and highly sensitive Cu2+ detection devices in organic media before. In this report, CsPbBr3 perovskite quantum dots (PQDs) are employed as fluorescence probe for Cu2+ detection in microfluidic chip. The size effect of the CsPbBr3 QDs on the detection performances is firstly investigated. To obtain preferable sensitivity and detection limit, polymethyl methacrylate opal photonic crystals (PMMA OPCs) film is developed as microfluidic sensor substrate, which can tremendously improve the fluorescence intensity of PQDs as high as 26-fold. The enhancement effect can be attributed to the coupling between photonic crystal stopband effect and the excitation light field. Moreover, the use of photomultiplier module for fluorescence signal measurement enables the detection device to be portable. The novel strategy offers the advantages of higher sensitivity (8.62 μM–1) and lower detection limit (0.40 nM). Otherwise, this sensor also provides wide detection range and good selectivity, thus, it will have potential in oil quality in-situ detection and mechanical wear prediction in the future.

中文翻译：

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用于高灵敏度原位检测润滑油中铜离子的荧光增强微流体传感器

摘要 船用电厂润滑油中Cu2+的灵敏在线检测对于实时显示设备磨损状态和故障预判具有重要意义。然而，之前关于有机介质中原位、便携式和高灵敏度Cu2+检测装置的报道很少。在本报告中，CsPbBr3 钙钛矿量子点（PQDs）被用作微流控芯片中 Cu2+ 检测的荧光探针。首先研究了 CsPbBr3 QD 对检测性能的尺寸效应。为了获得更好的灵敏度和检测限，聚甲基丙烯酸甲酯蛋白石光子晶体（PMMA OPCs）薄膜被开发为微流体传感器基板，它可以极大地提高 PQDs 的荧光强度高达 26 倍。增强效应可归因于光子晶体阻带效应与激发光场之间的耦合。此外，使用光电倍增管模块进行荧光信号测量使检测装置具有便携性。这种新颖的策略具有更高的灵敏度 (8.62 μM–1) 和更低的检测限 (0.40 nM) 的优势。此外，该传感器还具有较宽的检测范围和良好的选择性，因此在未来油质原位检测和机械磨损预测方面具有潜力。