Fluorescence sensing of nitrophenol explosives using a two-dimensional organic-metal chalcogenide fully covered with functional groups

Engineering of CdS-chain arrays assembled through S⋯S interactions in 1D semiconductive coordination polymers

One-dimensional (1D) Cd(II) coordination polymers [Cd(x-SPhOMe)2]n (x = ortho, meta, and para; HSPhOMe = methoxybenzenethiol) containing inorganic 1D (-Cd-S-)n chains were synthesized. Among these, the KGF-31 polymer bearing para-SPhOMe featured a three-strand chain structure assembled via interchain S⋯S interactions and exhibited high photoconductivity and longevity.

Regulating donor-acceptor system toward highly efficient dual-state emission for sensitive response of nitroaromatic explosives

Dual-state emission luminogens (DSEgens) as fluorophores emit efficiently in solution and solid forms have gained increasing concern in the field of chemical sensing. Recent efforts by our group led to the identification of DSEgens as an easy-to-visualize nitroaromatic explosives (NAEs) detection platform. However, none of the previously studied NAEs probes show effective improvement in sensitivity. Here, we designed a series of benzoxazole-based DSEgens through multiple strategies driven by theoretical calculations, revealing their improved detecting performance on NAEs. Compounds 4a-4e exhibit thermal- and photo-stability, large Stokes shift as well as sensitivity solvatochromism (except for 4a and 4b). A subtle balance between rigid conjugation and distorted conformation endows these D-A type fluorophores 4a-4e with DSE properties. Furthermore, 4d and 4e show aggregation-induced emission phenomenon caused by distorted molecular conformation and restricted intramolecular rotation. Interestingly, DSEgen 4e displays anti-interference and sensitivity towards NAEs with a detection limit of 10^-8 M. It can be applied for expedient and distinct visual identification of NAEs not only in solution but also on filter paper and film, supporting this new DSEgen as reliable NAEs chemoprobe.

Non-aqueous onion like nano-carbons from waste diesel-soot used as FRET-based sensor for sensing of nitro-phenols

Herein, a simple-functionalization method is described to prepare the oleylamine functionalized non-aqueous version of onion-like nanocarbons (ONC-OA), where ONC was isolated from the waste pollutant soot exhausted from the diesel engine. The surface group analysis of ONC-OA has been investigated via Nuclear Magnetic Resonance and X-ray Photoelectron Spectroscopy. ONC-OA shows blue fluorescence with a quantum yield of ∼6% in tetrahydrofuran (THF). The fluorescence-based sensing applications of ONC-OA has been investigated for selective sensing of toxic aromatic nitro-phenols compounds (para-nitro, dinitro, and trinitro phenols) from the tested many nitro organic compounds. Based on the limit of detection values, ONC-OA shows much better results for tri-nitro phenol compared to di and mono nitrophenol. To understand the quenching mechanism, a time-resolved photoluminescence analysis of the sensor with and without the addition of quenchers is performed. The effective lowering in fluorescence lifetime of the sensor after the addition of quenchers concludes that the quenching observed is majorly due to the Förster Resonance Energy Transfer (FRET) mechanism. The real-life application of ONC-OA was analyzed by external spiking of N-PhOHs in soil samples.