Dual-mode Detection of Dopamine Based on Enhanced Fluorescent and Colorimetric Signals of Fe3+-H2O2-o-Phenylenediamine System

Publication date: August 2018Source: Chinese Journal of Analytical Chemistry, Volume 46, Issue 8Author(s): Chuan-Xia CHEN, Peng-Juan NI, Yuan-Yuan JIANG, Zhen-Lu ZHAO, Yi-Zhong LUAbstractA fluorescent and colorimetric dual-mode “light-on” assay for the detection of dopamine (DA) was developed based on Fe3+-H2O2-OPD system. In general, Fe3+ could catalyze the H2O2-mediated oxidation of colorless and nonfluorescent o-phenylenediamine (OPD), and the resultant 2,3-diaminophenazine (DAP) exhibits a visible yellow color and yellow fluorescence. However, the reaction rate is extremely slow. By comparison, the introduction of DA can trigger a typical Fenton reaction that generates hydroxyl radical (−OH) continuously, thus increasing the conversion rate of OPD to DAP. Correspondingly, both color and fluorescence of the sensing system are enhanced obviously. On the basis of this fact, a sensor with dual readout for the detection of DA was established via measuring the fluorescent and colorimetric signals of the Fe3+-H2O2-OPD system. The linear ranges were 0.05–20 mM and 0.10–18 mM, and the detection limits were calculated to be 15 and 65 nM (S/N = 3) for fluorescent and colorimetric detection, respectively. The proposed dual-readout method features with simplicity, high sensitivity, visualization and good accuracy. Moreover, the method has been successfully applied to the detection of DA in human urine with satisfactory results.Graphical AbstractIntroducing DA into the Fe3+-H...

Source: Chinese Journal of Analytical Chemistry - July 27, 2018 Category: Chemistry Source Type: research