Molecular insights into multi-channel detection of nitrophenol explosives and acids in covalent organic frameworks with diverse hydrazone moieties

Emissive Covalent Organic Frameworks: Fluorescence Improvement via a Controllable Vertex Strategy and Chemical Sensing

“…The K SV was estimated to be as high as 10 5 M –1 for both COFs (Figure S16), which are much better than those of the reported COFs (Table S1). − Both COFs showed low K SV values for other compounds. For example, HE-COF exhibited values at 20, 17, 6, and 6% for DNP, DNT, NP, and NT, respectively (Figures S17b–S20b).…”

“…The limit of detection (LOD) value of HE-COF ranked excellent among the reported COF detectors (Table S1). − The Stern–Volmer constant ( K SV ) was determined for the TNP using the fluorescence quenching profiles. The K SV was estimated to be as high as 10 5 M –1 for both COFs (Figure S16), which are much better than those of the reported COFs (Table S1).…”

“…Covalent organic frameworks (COFs) represent an attractive class of porous materials that have received great attention owing to their unique properties and versatile utilization. − COFs are typically constructed by linking organic building units through covalent bonds, resulting in the formation of a crystalline polymer. − As benefits of these features, COFs exhibited low weight density and stable structure. − The covalent bonds give the framework good stability, producing robust COF materials. COFs offer tunable properties in terms of their topology and pore structure. − The geometry and size of the organic building units can be adjusted to create a wide variety of COF structures with different properties and applications. − COFs have been extensively researched and have found applications in various fields, including gas uptake, catalysis, energy storage, and emissive sensors. − …”

A fluorescent hydrogen-bonded organic framework for highly selective sensing of mono-nitrophenol isomers in water

“…These K sv values are comparable to those of many promising sensing materials reported (Table S2†), such as BUT-12 (4.2 × 10 4 ) 4 and Pythz-COF (4.4 × 10 4 ). 26 Based on the K sv values and the standard deviations, the limit of detection (LOD) of HOF-TPE-CN toward ONP, MNP, and PNP were calculated to be 1.1 μM, 2.39 μM, and 0.65 μM, respectively (see the details in the ESI†), which are lower than most of the promising crystalline sensing materials, including Th-TCBPE (0.7 μM), 25 Pyaph-COF (42 μM), 26 and CHOF-1 (8.78 μM). 27 It is worthy of note that most of the related sensing reports were performed in organic solvents (Table S2†).…”

Recent Progress of Covalent Organic Frameworks Applied in Electrochemical Sensors

“…COF-based fluorescent sensors for explosives detection have been reported frequently, − but COF-based electrochemical detection of explosives is rare. Zhao and co-workers prepared a pillararene and Au NPs functionalized COF and applied it to the sensitive and rapid detection of sodium picrate (SP) and picric acid (PA) .…”