Ultrasensitive Fluorescence Detection of Peroxymonosulfate Based on a Sulfate Radical-Mediated Aromatic Hydroxylation

Abstract

Recently, peroxymonosulfate (PMS)-based advanced oxidation processes have exhibited broad application prospects in the environment field. Accordingly, a simple, rapid, and ultrasensitive method is highly desired for the specific recognition and accurate quantification of PMS in various aqueous solutions. In this work, SO 4•− -induced aromatic hydroxylation was explored, and based on that, for the first time, a novel fluorescence method was developed for the PMS determination using Co 2+ as a PMS activator and benzoic acid (BA) as a chemical probe. Through a suite of spectral, chromatographic, and mass spectrometric analyses, SO 4•− was proven to be the dominant radical species, and salicylic acid was identified as the fluorescent molecule. As a result, a whole radical chain reaction mechanism for the generation of salicylic acid in the BA/PMS/Co 2+ system was proposed. This fluorescence method possessed a rapid reaction equilibrium (<1 min), an ultrahigh sensitivity (detection limit = 10 nM; quantification limit = 33 nM), an excellent specificity, and a wide detection range (0−100 μM). Moreover, it performed well in the presence of possible interfering substances, including two other peroxides (i.e., peroxydisulfate and hydrogen peroxide), some common ions, and organics. The detection results for real water samples further validated the practical utility of the developed fluorescence method. This work provides a new method for the specific recognition and sensitive determination of PMS in complex aqueous solutions.

Efficient Removal of Organic Pollutants by Metal–organic Framework Derived Co/C Yolk–Shell Nanoreactors: Size-Exclusion and Confinement Effect

“…The yield of SO 4 •– is important index to evaluate the activation of catalyst for PMS. − To further investigate the relationship between catalyst structures and yield of SO 4 •– in HA system, benzoic acid is used as chemical probe . As shown in SI Figure S7­(a), (c), (e), when catalysts are added into the PMS/BA/HA system, salicylic acid as SO 4 •– -induced aromatic hydroxylation resultant has been detected at E m = 403 nm.…”

First Direct and Unequivocal Electron Spin Resonance Spin-Trapping Evidence for pH-Dependent Production of Hydroxyl Radicals from Sulfate Radicals

“…The sulfate radical (SO 4 • – ) has been found to exhibit broad application prospects in various research fields such as chemical, biomedical, and environmental sciences. − Recently, SO 4 • – has drawn special attention due to its high efficiency of mineralization of organic pollutants. ,, SO 4 • – has a redox potential of approximately 2.6 V (the reported values range from 2.5 to 3.1 V, reaction ), which is similar to that of hydroxyl radical ( • OH) 2.7 V (reaction ). ,,, SO 4 • – can be produced from the activation of persulfate (including peroxodisulfate (PDS) and peroxymonosulfate (PMS)) by UV, , heat, base, ozone, transition metals, and quinones .…”

“… ,,, SO 4 • – can be produced from the activation of persulfate (including peroxodisulfate (PDS) and peroxymonosulfate (PMS)) by UV, , heat, base, ozone, transition metals, and quinones . Because of its high reactivity, selectivity, and widely operational pH range, , SO 4 • – has been extensively investigated as an alternative to • OH-based advanced oxidation processes (AOPs), especially for the control of micropollutants such as algal toxins, perfluorinated compounds, flame retardants, and endocrine disruptors. − SO 4 • – has also been widely used in many other fields such as in biological research, ,− analytical chemistry, ,− organic synthesis, , and public health (as a disinfection agent) (For more details, see Table S1). …”

Carbocatalytic ozonation toward advanced water purification

“…In addition, the amount of ROS can be semi-quantied by measuring the degradation reaction constants of chemical probes and the concentration of the generated byproducts. Probes such as p-chlorobenzoic acid, [243][244][245] benzoic acid, 246,247 salicylic acid, 248,249 N,N-dimethyl-p-nitrosoaniline, 250 dimethyl sulfoxide, 251,252 terephthalic acid 253,254 and 1,5-diphenylcarbohydrazide 255 can be employed for HOc detection. For example, HOc can convert the non-uorescent salicylic acid to the uorescent 2,3-dihydroxybenzoic acid.…”