Covalent Organic Frameworks as Advanced Uranyl Electrochemiluminescence Monitoring Platforms

Abstract

Electrochemiluminescence (ECL), as an advanced sensing process, can selectively control the generation of excited states by changing the potential. However, most of the existing ECL systems rely on poisonous coreactants to provide radicals for luminescence; although the ECL efficiency was improved, the athematic coreactants will cause unpredictable interference to the accurate analysis of trace targets. Herein, we realized the ECL of nonemitting molecules by performing intramolecular electron transfer in the olefin-linked covalent organic frameworks (COFs), with a high efficiency of 63.7%. Employing internal dissolved oxygen as the coreactant, it is well suitable for the analysis of various complex samples in the environment. Taking nuclear contamination analysis as the goal orientation, we further illustrated a design of a "turn-on" uranyl ion monitoring system integrating fast response, low detection limit, and high selectivity, showing that new ECL-COFs are promising to facilitate environment-related sensing analysis and structure-feature correlation mechanism exploration.

Intrareticular electron coupling pathway driven electrochemiluminescence in hydrogen-bonded organic frameworks

“…Interestingly, the ECL efficiency of HOF-101/K 2 S 2 O 8 was as high as 64.7% compared with that of the 0.1 mM Ru(bpy) 3 2+ /TPrA (20 mM) system (Fig. S32, ESI†), which is superior to 5.22% of the conductive COF/K 2 S 2 O 8 system, 51 57.10% of donor–acceptor COFs, 52 21.3% of triazinyl HOF, 29 and 15.9% of the Zn-tetracarboxylate MOF/K 2 S 2 O 8 system (Table S7, ESI†). 53…”

“…Interestingly, the ECL efficiency of HOF-101/K 2 S 2 O 8 was as high as 64.7% compared with that of the 0.1 mM Ru(bpy) 3 2+ /TPrA (20 mM) system (Fig. S32, ESI †), which is superior to 5.22% of the conductive COF/K 2 S 2 O 8 system, 51 57.10% of donor-acceptor COFs, 52 21.3% of triazinyl HOF, 29 and 15.9% of the Zntetracarboxylate MOF/K 2 S 2 O 8 system (Table S7, ESI †). 53 According to the calculation by HSE06 screened hybrid DFT, the expanded aromatic HOF-101 showed the entire CBM delocalization on both the pyrene core and four benzene arms, providing a larger p-conjugated structure than HOF-100.…”

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

“…772,773 The Qiu group reported some COFs with electrochemiluminescence properties 774,775 and their application in UO 2 2+ detection. 776,777 Briefly, electrochemical sensing has the advantages of sensitive response, simple operation, and low cost, but metal-free COFs have not been widely used in electrochemical sensing due to their poor electrical conductivity. By contrast, metal nanoparticle-loaded COFs to some extent cover the shortage of low conductivity and have been developed for electrochemical sensing, but there is still room for improvement in reproducibility and stability.…”

“…772,773 The Qiu group reported some COFs with electrochemiluminescence properties 774,775 and their application in UO 2 2+ detection. 776,777…”

Interpenetrating porous photonic crystal balls for rapid naked eye detection of uranyl ions

“…Uranium in compounds has various oxidation states; the most stable and common in nature is the uranyl ion (UO 2 2+ ), which is easily accumulated in organisms. According to the US Environmental Protection Agency (EPA), the maximum pollution standard for UO 2 2+ in drinking water is 130 × 10 −9 M. 4 In the past few decades, some methods, such as inductively coupled plasma-mass spectrometry (ICP-MS), 5 inductively coupled plasma-atomic emission spectroscopy (ICP-AES), 6 atomic absorption spectroscopy (AAS), 7 X-ray fluorescence spectroscopy (XFS), 8 surface-enhanced Raman scattering (SERS), 9,10 and electrochemiluminescence (ECL) analysis, [11][12][13] have been developed to detect UO 2 2+ . Although the methods mentioned above have their distinct advantages, most of them require expensive instruments and professional operators, which has prompted some researchers to focus on convenient field-operable fluorescence chromogenic and complexometric titration techniques.…”