Shao-Lin Wang

Bio: Shao-Lin Wang is an academic researcher from University of Science and Technology of China. The author has contributed to research in topics: Phosgene & Triphosgene. The author has an hindex of 5, co-authored 5 publications receiving 151 citations.

Sensitive and Selective Detection of Phosgene, Diphosgene, and Triphosgene by a 3,4-Diaminonaphthalimide in Solutions and the Gas Phase.

Abstract: Phosgene and its substitutes, diphosgene and triphosgene, are highly toxic and widely used chemicals, so it is necessary to investigate their reactivity and develop facile, sensitive, and specific methods for detecting them. In this work, we have developed a new 1,8-naphthalimide-based fluorescent chemosensor, Phos-2, which exhibits high sensitivity (detection limits: 0.2-0.7 nm), high selectivity to phosgene and its substitutes over nitric oxide (NO), various acyl chlorides, and nerve agent mimics in solutions. Based on investigation of the reaction kinetics of Phos-2 with phosgene and its substitutes, a two-step sensing mechanism was clarified. The second-order rate constants (k2 ) of Phos-2 reveal that the relative rate constants of phosgene, diphosgene, and triphosgene are 40:4:1. Moreover, a Phos-2 test paper has been fabricated as a low-cost, sensitive (≈5 ppm from observation by the naked eye or 0.1 ppm from a measurement), and efficient method for visual detection of a low concentration of phosgene in the gas phase.

Fluorescent Chemosensor for Dual-Channel Discrimination between Phosgene and Triphosgene

Abstract: As highly toxic and accessible chemical reagents, phosgene and triphosgene have become a serious threat to public safety. So, it is highly desirable to develop facile methods to detect and recognize them. In this article, a novel fluorescent chemosensor, Phos-4, has been constructed with 1,8-naphthalimide as the fluorophore and 2-(2-aminophenyl)imidazol as the recognition sites for discrimination between phosgene and triphosgene in a dual-channel mode for the first time. Owing to the difference in electrophilicity between chlorocarbonyl and trichloromethoxycarbonyl, the sensing reaction of Phos-4 with phosgene undergoes two carbamylations to afford a cyclic product with green fluorescence, and only one carbamylation occurs for triphosgene to form a noncyclic product with blue fluorescence. The sensor Phos-4 exhibits high sensitivity (the limit of detection, 3.2 nM, for phosgene, and 1.9 nM, for triphosgene) and high selectivity in solutions. Furthermore, facile test papers containing Phos-4-embedded nanofibrous membrane have been fabricated by the electrospinning technology. The test papers can provide visual and selective detection of phosgene with a lower limit of detection (42 ppb) and a faster response (≤10 s) in the gas phase over those in solutions. The test paper with Phos-4 is promising to be a practical detection tool of gaseous phosgene.

Selectively instant-response nanofibers with a fluorescent chemosensor toward phosgene in gas phase

Abstract: Owing to the distinct advantages such as facility, low cost and simplicity, fluorescent chemosensors are highly suitable for field detection and rapid screening of suspected chemical warfare agents (CWAs) such as phosgene. For an effective fluorescent chemosensor, instantaneous response to phosgene is one of the several key considerations in practical applications. In this paper, we reported a fluorescent chemosensor, Phos-3, constructed with o-diamine moiety as the active site, which includes one aliphatic primary amine and one aromatic secondary amine for rapid and selective detection of phosgene via colorimetric and ratiometric fluorescence response. The sensing reaction involved two successive carbamylations between Phos-3 and phosgene. The aliphatic amine of o-diamine possessed stronger nucleophilicity than the aromatic amine and could undergo fast intermolecular (the first) carbamylation with phosgene. The second intramolecular carbamylation was accelerated since the pentacyclic moiety limited the C–N rotation of o-diamine. As a result, the sensing reaction displayed a rapid optical response (∼60 s in solutions) with high sensitivity (LOD = 0.3 nM) and high selectivity. Importantly, Phos-3-embedded polymer nanofibers were prepared by the electrospinning technique for the detection of phosgene in the gas phase. These nanofibers embedded with Phos-3 displayed a quick response (≪1 s) to phosgene with high sensitivity (LOD = 25 ppb) and high selectivity. This study will pave the way for its practical application in rapid screening of phosgene in suspected gas samples.

The sensing property of charge-transfer chemosensors tuned by acceptors for colorimetric and fluorometric detection of CN−/HCN in solutions and in gas phase

Abstract: Cyanide ion (CN−) is highly toxic, and its wide use in industry poses an immediate threat to public safety. Consequently, it is desired to develop reliable and facile methods to detect this dangerous chemical. In this work, four diethylaminoquinoline derivatives (3a–3d) with different 2-vinyl substituents have been constructed for the detection of CN−/HCN via a Michael addition. The electrophilicity of the β-carbon of 2-vinyl group depends on the electron-withdrawing ability of the substituents, which tune the photophysical properties of sensors and sensing products by varying intramolecular charge transfer (ICT). Among these sensors, 3a displays the best sensing behavior towards CN−, that is, rapid colorimetric and ratiometric fluorescent response (∼10 s), high sensitivity (LOD = 15 nM) and high selectivity in solutions. The sensing mechanism of a two-step reaction has been clearly demonstrated by 1H NMR, HRMS and tracking and titration experiments. Moreover, the test strip with 3a has been fabricated with a polyethyl oxide and successfully applied to detect HCN gas (60 ppm) visually and selectively.

Recent Advances in the Development of Chromophore-Based Chemosensors for Nerve Agents and Phosgene

Abstract: The extreme toxicity and ready accessibility of nerve agents and phosgene has caused an increase in the demand to develop effective systems for the detection of these substances. Among the traditional platforms utilized for this purpose, chemosensors including surface acoustic wave (SAW) sensors, enzymes, carbon nanotubes, nanoparticles, and chromophore based sensors have attracted increasing attention. In this review, we describe in a comprehensive manner recent progress that has been made on the development of chromophore-based chemosensors for detecting nerve agents (mimic) and phosgene. This review comprises two sections focusing on studies of the development of chemosensors for nerve agents (mimic) and phosgene. In each of the sections, the discussion follows a format which concentrates on different reaction sites/mechanisms involved in the sensing processes. Finally, chemosensors uncovered in these efforts are compared with those based on other sensing methods and challenges facing the design of mor...

BODIPY-Based Fluorescent Sensor for the Recognization of Phosgene in Solutions and in Gas Phase

Abstract: As a highly toxic and widely used chemical, phosgene has become a serious threat to humankind and public security because of its potential use by terrorists and unexpected release during industrial accidents. For this reason, it is an urgent need to develop facile, fast, and selective detection methods of phosgene. In this Article, we have constructed a highly selective fluorescent sensor o-Pab for phosgene with a BODIPY unit as a fluorophore and o-phenylenediamine as a reactive site. The sensor o-Pab exhibits rapid response (∼15 s) in both colorimetric and turn-on fluorescence modes, high selectivity for phosgene over nerve agent mimics and various acyl chlorides and a low detection limit (2.7 nM) in solutions. In contrast to most undistinguishable sensors reported, o-Pab can react with phosgene but not with its substitutes, triphosgene and biphosgene. The excellent discrimination of o-Pab has been demonstrated to be due to the difference in highly reactive and bifunctional phosgene relative to its subst...

1,8-Naphthalimide-based fluorescent chemosensors: recent advances and perspectives

Abstract: 1,8-Naphthalimide, as one of the classical dyes and fluorophores, has been widely used in analytical chemistry, materials chemistry, and biochemistry fields because of its excellent characteristic photostability, good structural flexibility, high fluorescence quantum yield, and large Stokes shift. This review mainly focuses on 1,8-naphthalimide and its derivatives in ion detection, molecular recognition, material applications, and bioimaging in the past five years. Simultaneously, we hope to develop more powerful fluorescent chemosensors for broad and exciting applications in the future.

An ESIPT-Based Fluorescence Probe for Colorimetric, Ratiometric, and Selective Detection of Phosgene in Solutions and the Gas Phase.

Abstract: Phosgene is a highly toxic substance that has become a serious potential threat to public health safety. A colorimetric and ratiometric fluorescence probe 1 for phosgene has been developed based on an ESIPT process. Both the visible colorimetric change from colorless to yellow and the fluorescent color change from blue to green (under 365 nm hand-held UV lamp) can be easily observed by the naked eye. Probe 1 has a high sensitivity and selectivity for phosgene in solutions and the gas phase. The mechanism for sensing by 1 was investigated by using high-resolution mass spectrometry and 1H NMR and 13C NMR spectroscopies.