Oxime-functionalized anti-insecticide fabric reduces insecticide exposure through dermal and nasal routes, and prevents insecticide-induced neuromuscular-dysfunction and mortality

Interfacial Asymmetrically Coordinated Zn-MOF for High-Efficiency Electrosynthetic Oxime

Oximes are important intermediates for various chemicals synthesis such as pharmaceuticals, among which one vital precursor for producing neurological disease, antimicrobial and anticancer agents is piperidone oxime (PDO). Compared with conventional thermocatalytic method, it's more attractive to synthesize PDO via green electrocatalytic technology especially utilizing waste nitrogen oxides gas as nitrogen source. However, there are great challenges in catalyst design for high-efficiency electrosynthetic oxime due to the low electron transport rate and multiple competing reactions. Herein, we propose an interfacial coordination strategy based on metal-organic frameworks (MOF) electrocatalyst for the first time to promote oxime electrosynthesis, by building Zn-O bridges between graphite felt (GF) and zeolitic imidazolate framework (ZIF-7/CGF). Specially, ZIF-7/CGF delivers a Faraday efficiency (FE) of 75.9 % with yield up to 73.1 % for 1-methyl-4-piperidone oxime, which is far superior to the catalyst without Zn-O bridges (a FE of 10.7 % and yield of 10.3 %). In-depth mechanism study shows that the introducing Zn-O bridges can promote the electron transfer and induce Zn sites transforming into distorted tetrahedron (Zn-N3O) coordination mode, which benefits for intermediates adsorption and conversion. The developed strategy presents wide universalities towards various oximes electrosynthesis and adapts to other MOF materials (ZIF-8, ZIF-4). This work provides new insights for electrosynthetic organic chemicals and upgrading nitrogen cycle through rational design surficial coordinated electrocatalysts.

p-AAB/MXene as a novel adsorbent and SALDI matrix for highly efficient enrichment and rapid MS detection of emerging environmental organic pollutants in beverages and PM2.5

Due to the complicated sample matrix and low concentration, analysis of small-molecule emerging environmental pollutants generally required complex sample preparation and long instrumental detection. It guarantees the sensitivity but is not conducive to rapid screening. In this work, a p-aminoazobenzene (p-AAB) with excellent energy absorption capability was used to modify multilayer Ti3C2TX (MXene) to prepare novel material p-AAB/MXene. The modification significantly improved the laser absorption of original material, and made p-AAB/MXene could be employed as matrix for surface-assisted laser desorption/ionization-time of flight-mass spectrometry (SALDI-TOF MS) analysis of small-molecule emerging pollutants. More importantly, p-AAB/MXene could be used as adsorbent to enrich target compounds, then directly sent to SALDI-TOF MS detection without any other sample pre-treatment. Dual characteristics of enrichment material and matrix made p-AAB/MXene-based SALDI-TOF MS method successfully be applied to rapid and accurate detection of emerging environmental pollutants, p-phenylenediamine-quinones (PPDQs) and diamide insecticides (DAIs), in food (beverage) and environmental (PM2.5) samples. High sensitivity (LOD at ng mL-1 level) and satisfactory precision (RSD < 11%) indicated the qualified analytical performance of developed approach. The determined concentrations also elucidated the broad occurrence of PPDQs and DAIs in beverages and PM2.5. The results further confirmed the SALDI-TOF MS using p-AAB/MXene as both adsorbent and matrix had considerable potential for efficient and time-saving analysis of trace and ultra-trace small-molecule emerging environmental organic pollutants in complicated samples.