Portable dual-mode microfluidic sensor for rapid and sensitive detection of DPA on chip

作者：Xiaodong Lin, Zhengyang Cao, Shiyu Zeng, Haoyu Zhu, Kairui Zhai, Binfeng Yin, Cheng Zhang, Tao Peng, Teng Cheng, Biao Zhang · 发表于：Advanced Composites and Hybrid Materials · 年份：2025 · DOI：10.1007/s42114-025-01320-2 · 被引用次数：27 · 研究领域：Analytical Chemistry and Sensors、Electrochemical sensors and biosensors、Analytical chemistry methods development

Abstract In this work, we developed a dual-mode portable device that integrated a 3D-printed microfluidic chip for detection of dipicolinic acid (DPA) on chip. The system uses a ratiometric fluorescence nanoprobe formed by embedding carbon dots (CDs) into an Eu 3 ⁺ metal–organic framework (Eu-MOF). Upon reaction with DPA in the microchannel, red fluorescence was enhanced and blue fluorescence suppressed, enabling sensitive ratiometric detection of DPA on chip with a detection limit (LOD) of 0.04 µM. Interestingly, the composite Eu MOF /CDs/DPA also exhibits peroxidase-like activity, catalyzing the oxidation of TMB into a blue-colored product (oxTMB), which allows for colorimetric detection with an LOD of 10.14 µM. To improve usability and reduce environmental or instrumental variability, incorporating a microfluidic chip into a semi-portable device and utilizing a smartphone, making the system portable and miniaturized for easy operation. In the smartphone-assisted mode, the LODs were 0.33 µM (ratiometric fluorescence) and 12.27 µM (colorimetry), determined by RGB signal analysis, respectively. Moreover, satisfactory recoveries (85–104.6%) were achieved in the spiked real samples. Overall, this platform offers a straightforward, cost-effective, and versatile approach for DPA detection, with promising applications in food safety, environmental monitoring, and clinical diagnostics.