Direct Blue Light-Induced Autocatalytic Oxidation of o-Phenylenediamine for Highly Sensitive Visual Detection of Triaminotrinitrobenzene

Abstract

o-Phenylenediamine (OPD)-based chromogenic reactions are worthy tools for the development of visual colorimetric assays. The chromogenic reactions are usually triggered by various oxidants, which is not easily tunable and incompatible with some analytes. Herein, we report that direct blue light irradiation can induce the autocatalytic oxidation of OPD to generate 2,3-diaminophenazine (oxidized-state OPD, oxOPD). The autocatalytic photo-oxidation reaction mechanism of OPD is mainly ascribed to the resonant energy transfer between ectronically excited oxOPD and dissolved oxygen to form singlet state oxygen with a high oxidation capacity, which accelerates the oxidation of OPD. We demonstrate that under neutral and alkaline environment, the photoinduced autocatalytic oxidation of OPD is able to be further enhanced by triaminotrinitrobenzene (TATB) explosive because of its inhibition effect on the aggregation caused quenching phenomenon of oxOPD. On this basis, a straightforward visual colorimetric assay for TATB with a tunable dynamic range is developed. This assay is capable of detecting TATB explosive concentrations as low as 2.7 nM. Notably, the obvious color change after addition of TATB enables a naked-eye readout with the lowest detectable TATB concentrations of 60 nM.

Cascade Chromogenic System with Exponential Signal Amplification for Visual Colorimetric Detection of Acetone

“…The corresponding absorbance value of the cascade chromogenic system at 446 nm is 5.9 and 13 times higher than those of Fe 3+ -triggered chemical oxidation and direct blue-light-induced oxidation of OPD, respectively. It should be noted that, when the OPD concentration is higher than 5 mM, direct blue-light illumination can induce the OPD oxidation because partial OPD is oxidized by dissolved oxygen to yield DAP that autocatalytically oxidizes OPD …”

Fluorescent and Colorimetric Sensors Based on the Oxidation of o-Phenylenediamine

“…Recently, Wang et al developed a sensitive and facile visual colorimetric assay for the detection of TATB based on the direct blue light induced autocatalytic oxidation of OPD ( Scheme 15 ). 25 Under the irradiation of blue light, OPDox is electronically excited and interacts with dissolved oxygen through resonant energy transfer to form a singlet-state oxygen, which possesses high oxidation capability and in turn accelerates the oxidation of OPD. Additionally, TATB can further enhance this photoinduced autocatalytic reaction, because the noncovalent interactions between TATB and OPDox can prevent the π–π stacking of OPDox and eliminate aggregation caused quenching (ACQ).…”

Label-free colorimetric detection of glutathione by autocatalytic oxidation of o-phenylenediamine based on Au3+ regulation and its application

“…The limit of detection (LOD) was as low as 0.08 nM, and the signal-to-noise ratio was 3 (S/N = 3); such a good sensitivity may be due to the strong molar extinction coefficient of ox OPD (e = 2.1 Â 10 4 M À1 Ácm À1 , 30 ). Previous literature 26,31,32 confirmed that the target reactant can be detected in nanomolar concentrations through an OPD-based sensor. Compared with several reported methods based on other nanomaterials, [33][34][35][36] our method has lower LOD and higher sensitivity.…”