A Heterogeneous Nanoscale Covalent Organic Framework Fluorescence Probe for Sensitive Detection of Hydrogen Sulfide

Abstract

New strategies for highly selective and sensitive detection of highly toxic environmental pollutants are still a pressing need. Here, through Cu2+ metalated porous nanoscale covalent organic framework (NCOF), a novel heterogeneous NCOF fluorescence probe has been synthesized for sensitive and selectivity detection of hydrogen sulfide (H2S). Upon H2S addition, the Cu2+ released from the CuCOF, accompanied by the fluorescence recovered of COF. As far as we know, NCOF has not been reported as fluorescence probe for H2S detection. The as‐prepared nano CuCOF displays an excellent sensitive response to H2S with a detection limit of 10 nM. In addition, such heterogeneous fluorescence probe exhibited high selectivity towards to H2S relative to other thiols and anionic species. Moreover, the detection of H2S was achieved successfully in different actual water samples.

Self-Exfoliating Double-Emission N-Doped Carbon Dots in Covalent Organic Frameworks for Ratiometric Fluorescence “Off–On” Cu2+ Detection

“…In the past few years, many fluorescent sensors for Cu 2+ detection have been reported. However, most of the reported Cu 2+ fluorescent sensors are based on Cu 2+ paramagnetic properties, which cause a quenching of fluorescence emission and give an “on–off” signal. − However, in certain circumstances, the fluorescence on–off signal may provide inaccurate results. − Compared with a fluorescent on–off Cu 2+ sensor, a fluorescent “off–on” signal probe can interact with Cu 2+ to enhance the fluorescence and has higher sensitivity and accuracy . At present, some reports have demonstrated that nitrogen-containing groups with electron-donating units can achieve off–on fluorescence detection of Cu 2+ . , Fluorescent sensors with Cu 2+ -induced off–on fluorescence signals are attracting more and more attention.…”

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

“…The metalated COF-based fluorescence visualization for intracellular H 2 S was reported very recently. In 2021, Du and co-workers reported a copper(II) porphyrin-based CuPor-COF for sensitive and selective detection of H 2 S. 756 As indicated by the authors, H 2 S could react with Cu(II) and release the metalfree COF to turn on the fluorescence (Fig. 56A).…”

Covalent Organic Frameworks: Recent Progress in Biomedical Applications

“…(c) Structure of CuCOF. (d) UV–vis spectrum of CuCOF before and after quenched by H 2 S. Adapted with permission from ref . Copyright 2021 Wiley-VCH.…”

“…Upon the addition of H 2 S, the intensity of fluorescence emission at 535 nm gradually increased because of the reduction of azide to an amino group (Figure 21b). 132 In 2021, Ge et al 133 developed another Cu 2+ -metalated porphyrinbased COF to detect H 2 S (Figure 21c) through the Cuextracting reaction between H 2 S and Cu 2+ ion, which led to the recovery of a fluorescent signal (Figure 21d). This CuCOF displayed a good selectivity and a low H 2 S detection limit of 10 nM.…”