Xu Zihe, Chen Xi, Liu Fangwu
Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Sensors (Basel). 2024 Sep 26;24(19):6224. doi: 10.3390/s24196224.
In many research fields, the demand for miniaturized laser-induced fluorescence (LIF) detection systems has been increasing. This work has developed a compact LIF detector, employing a laser diode as the excitation source and a photodiode as the photodetector with an adjustable laser focal spot, to meet the diverse requirements of various observation targets, such as capillaries, PCR tubes, and microfluidic chips. It features the functionalities of background fluorescence correction, the adaptive adjustment of the dynamic range, and constant power control for the laser. The influence of the excitation power on the detection limit was studied through experiments, and the configuration results for LED/LD as light sources and 487/450 nm wavelengths were compared and optimized. A fully integrated, compact, modular epifluorescence LIF detector was subsequently constructed, measuring 40 × 22 × 38 mm in total size, with a cost of USD 320, and achieving a detection limit of 0.4 nM for fluorescein sodium. Finally, the detector was integrated into a nucleic acid detection system with a microfluidic chip on the Chinese Space Station (CSS) and was also tested with PCR tubes and capillaries, proving its broad practicality and adaptability to various analytical systems.
在许多研究领域，对小型化激光诱导荧光（LIF）检测系统的需求一直在增加。这项工作开发了一种紧凑型LIF探测器，采用激光二极管作为激发源，光电二极管作为光电探测器，激光焦点可调，以满足对各种观察目标（如毛细管、PCR管和微流控芯片）的不同要求。它具有背景荧光校正、动态范围自适应调整和激光恒功率控制等功能。通过实验研究了激发功率对检测限的影响，并对以LED/LD作为光源和487/450 nm波长的配置结果进行了比较和优化。随后构建了一个完全集成、紧凑、模块化的落射荧光LIF探测器，总尺寸为40×22×38 mm，成本为320美元，对荧光素钠的检测限达到0.4 nM。最后，该探测器被集成到中国空间站（CSS）上带有微流控芯片的核酸检测系统中，并且还用PCR管和毛细管进行了测试，证明了其广泛的实用性和对各种分析系统的适应性。
