Guest Molecular Assembly Strategy in Covalent Organic Frameworks for Electrochemiluminescence Sensing of Uranyl

Abstract

The application of covalent organic frameworks (COFs) in electrochemiluminescence (ECL) is promising in environmental monitoring. Developing an emerging design strategy to expand the class of COF-based ECL luminophores is highly desirable. Here, a COF-based host−guest system was constructed through guest molecular assembly to deal with nuclear contamination analysis. The efficient charge transport network was formed by inserting an electron-withdrawing guest tetracyanoquinodimethane (TCNQ) into the open space of the COF host (TP-TBDA; TP = 2,4,6-trihydroxy-1,3,5-benzenetricarbaldehyde and TBDA = 2,5-di(thiophen-2-yl)benzene-1,4-diamine) with an electron-donating property; the construction of the COF-based host−guest system (TP-TBDA@TCNQ) triggered the ECL emission of non-emitting TP-TBDA. Furthermore, the dense active sites in TP-TBDA were utilized to capture the target substance UO 2 2+ . The presence of UO 2 2+ broke the charge-transfer effect in TP-TBDA@TCNQ, resulting in the weakening of the ECL signal, thus the established ECL system integrating the low detection limit with high selectivity monitors UO 2 2+ . This COF-based host− guest system provides a novel material platform for constructing late-model ECL luminophores and creates an opportunity for the vigorous ECL technology.

Hydrogen-Bonded Organic Cocrystal-Encapsulated Perovskite Nanocrystals as Coreactant-Free Electrochemiluminescent Luminophore for the Detection of Uranium

“…In the XPS survey spectra of PeNCs@NHS-M, two characteristic peaks for U 4f (392.8 eV for U 4f 5/2 and 381.8 eV for U 4f 7/2 ) can be observed, proving that UO 2 2+ chelated with PeNCs@NHS-M (Figure S22). As shown in Figure S23a, the N 1s high-resolution XPS spectrum of PeNCs@NHS-M-U formed a new N–U peak at 401.2 eV. Similarly, a new O–U peak (532.3 eV) was observed in the O 1s spectrum (Figure S23b).…”

Ultrathin alkynylation phthalocyanine-conjugated organic polymer nanosheets for constructing a sensitive electrochemiluminescence sensor

“…22 Similarly, multiple materials exhibit potential ECL because of their surface hole–electron annihilation luminescence. Recently, inorganic perovskite QDs, 23–25 upconversion nanoparticles, 26,27 aggregation-induced emission materials, 28 electroactive metal organic frameworks (E-MOFs), 29,30 and covalent organic frameworks (COFs) 31–33 have been reported as new ECL-active materials. Nevertheless, there are few studies focused on ECL-sensitive COPs.…”

Europium(III) Functionalized Covalent Organic Framework as Sensitive and Selective Fluorescent Switch for Detection of Uranium

“…In the development of nuclear energy, the exploitation of uranium resources and the discharge of uranium-containing wastewater during nuclear production are significant issues that cannot be ignored. − The presence of uranyl ions (UO 2 2+ ) in these wastewaters poses a serious threat to the environment due to their high toxicity and persistent nature. They can infiltrate into the soil, contaminate groundwater, and enter the food chain, causing long-term impacts on ecosystems and human health. − Therefore, it is crucial to develop effective detection methods to monitor and accurately measure the concentration of UO 2 2+ in uranium mine wastewater. − …”