State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China.
State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
Biosens Bioelectron. 2015 Aug 15;70:232-8. doi: 10.1016/j.bios.2015.03.043. Epub 2015 Mar 20.
We herein report a facile, one-step pyrolysis synthesis of photoluminescent carbon dots (CDs) using citric acid as the carbon source and lysine as the surface passivation reagent. The as-prepared CDs show narrow size distribution, excellent blue fluorescence and good photo-stability and water dispersivity. The fluorescence of the CDs was found to be effectively quenched by ferric (Fe(III)) ions with high selectivity via a photo-induced electron transfer (PET) process. Upon addition of phytic acid (PA) to the CDs/Fe(III) complex dispersion, the fluorescence of the CDs was significantly recovered, arising from the release of Fe(III) ions from the CDs/Fe(III) complex because PA has a higher affinity for Fe(III) ions compared to CDs. Furthermore, we developed an "off-on" fluorescence assay method for the detection of phytic acid using CDs/Fe(III) as a fluorescent probe. This probe enables the selective detection of PA with a linear range of 0.68-18.69 μM and a limit of detection (signal-to-noise ratio is 3) of 0.36 μM. The assay method demonstrates high selectivity, repeatability, stability and recovery ratio in the detection of the standard and real PA samples. We believe that the facile operation, low-cost, high sensitivity and selectivity render this CD-based "off-on" fluorescent probe an ideal sensing platform for the detection of PA.
我们在此报告了一种简便的一步热解法，使用柠檬酸作为碳源，赖氨酸作为表面钝化试剂，合成了发蓝色荧光的碳点（CDs）。所制备的 CDs 具有较窄的尺寸分布、优异的蓝光荧光性能、良好的光稳定性和水分散性。研究发现，通过光诱导电子转移（PET）过程，Fe(III)离子可以有效地猝灭 CDs 的荧光，具有较高的选择性。当向 CDs/Fe(III)配合物分散液中加入植酸（PA）时，由于 PA 与 Fe(III)离子的亲和力比 CDs 更强，因此 CDs 从 CDs/Fe(III)配合物中释放出来，导致 CDs 的荧光显著恢复。此外，我们开发了一种使用 CDs/Fe(III)作为荧光探针的“关-开”荧光分析方法来检测植酸。该探针能够选择性地检测 PA，线性范围为 0.68-18.69 μM，检测限（信噪比为 3）为 0.36 μM。该分析方法在检测标准和实际 PA 样品时具有高选择性、重现性、稳定性和回收率。我们相信，这种基于 CD 的“关-开”荧光探针具有操作简便、成本低、灵敏度高和选择性好的特点，是一种理想的用于检测 PA 的传感平台。
