The measurement of fluorescence emission for quantitative analysis is typically based on a traditional spectrofluorometer, which limits an onsite detection approach. Thus, an alternative device should be developed for fulfilling this analysis outside of the laboratory. Therefore, a low-cost, portable, and low-energy consumption fluorescence reader-based smartphone device was developed. An ultraviolet light-emitting diodes (UV-LED) was used to construct the fluorescence device-based smartphone as a low-power excitation light source. The smartphone camera was used as a detector for detecting photons from the fluorescence emission process of the fluorescence probe and was connected to a digital image platform. Transparent acrylic with orange and yellow colors was employed as a filter for reducing the interference from light source intensity. The obtained digital image was converted to red, green and blue (RGB) intensity using a custom-designed smartphone application. N,S-doped carbon nanodots (N,S-CDs) were demonstrated to be a good fluorescence indicator for determining trace quantities of Mn²⁺ in cosmetics. The approach exhibited high selectivity and sensitivity, detecting and quantifying analytes at 1–5 μM concentrations. Furthermore, the method's detection limit of 0.5 μM reflects its capacity to detect trace amounts of a target analyte. Mn²⁺ in cosmetic products was successfully analyzed using this device with high accuracy comparable with the results from inductively coupled plasma-optical emission spectroscopy (ICP-OES).

中文翻译：

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基于智能手机的便携式荧光检测装置，采用碳纳米点进行 Mn2+ 传感

用于定量分析的荧光发射测量通常基于传统的分光荧光计，这限制了现场检测方法。因此，应该开发一种替代设备来在实验室外完成这种分析。因此，开发了一种低成本、便携式、低能耗的基于荧光读取器的智能手机设备。紫外发光二极管（UV-LED）被用来构建基于荧光器件的智能手机作为低功率激发光源。智能手机摄像头用作检测器，用于检测荧光探针荧光发射过程中的光子，并连接到数字图像平台。采用橙色和黄色的透明亚克力作为滤光片，以减少光源强度的干扰。使用定制设计的智能手机应用程序将获得的数字图像转换为红、绿和蓝 (RGB) 强度。 N,S 掺杂碳纳米点 (N,S-CD) 被证明是一种很好的荧光指示剂，可用于测定化妆品中痕量 Mn ²⁺ 。该方法表现出高选择性和灵敏度，可检测和定量浓度为 1–5 μM 的分析物。此外，该方法的检测限为 0.5 μM，反映了其检测痕量目标分析物的能力。使用该设备成功分析了化妆品中的Mn ²⁺，其精度可与电感耦合等离子体发射光谱法 (ICP-OES) 的结果相媲美。