Design of an AIE-Active Flexible Self-Assembled Monolayer Probe for Trace Nitroaromatic Compound Explosive Detection

Abstract

In this work, a series of molecules TPE-PA-n (n = 3−11) were designed with classic aggregation-induced emission (AIE) 1,1,2,2-tetraphenylethene (TPE) for self-assembled monolayers (SAMs), which are applied for the detection of trace nitroaromatic compound (NAC) explosives. Phosphoric acid that acts as an anchor is used to connect with TPE through alkyl chains of various lengths. It is found that the alkyl chains play a role in pulling TPE luminogens to aggregate for light emission, which can affect the fluorescence and sensing performance of the SAMs. Ulteriorly, a model is built to explore the influence of the alkyl chain length on the device performance, which is determined by the three effects of the alkyl chain: flexibility, the coupling effect, and the odd−even effect. By comparison, the functional molecules with the chain length of 8 were finally selected and further applied for NAC sensors. By means of fluorescence spectra, the SAM sensor was proved to have good stability, reversibility, selectivity, and sensitivity, and its detection limits for trinitrotoluene, dinitrotoluene, and nitrobenzene were 1.2, 6.0, and 35.7 ppm, respectively. This work provides new ideas for the design and preparation of flexible sensors for trace NAC detection with high performance, low cost, and easy operation.

Nanometric Surface-Selective Regulation of Au/In2O3 Nanofibers as an Exhaled H2S Chemiresistor for Periodontitis Diagnosis

“…15 Notably, SAM modifications manifest specific advantages in facilitating the specific recognition and binding ability of sensing layers to target molecules. 16 Owing to the unique structure of the SAM, it is possible to improve sensing performance by adjusting the length of alkyl chains and the end groups, 17 as well as to achieve a hydrophobic surface of the material to adapt to humid environments. 18 For example, Singh et al 19 modified methyl (−CH 3 )-terminated tetraethyl orthosilicate (TEOS) on the ZnO nanowires and achieved a 3fold increase in response to acetone (C 3 H 6 O) at lower temperatures because of surface-specific interactions between −CH 3 and carbonyl groups of C 3 H 6 O.…”

Alkyl-Engineered Dual-State Luminogens with Pronounced Odd–Even Effects: Quantum Yields with up to 48% Difference and Crystallochromy with up to 22 nm Difference

“…However, alkyl chains are found to be able to tune the solid-state fluorescence (FL) by influencing the molecular packing modes . Particularly, the odd–even alternation of the FL quantum yield (FLQY) caused by alkyl chains is also observed in OLMs. − However, such an odd–even effect of FLQY is much less reported as compared to that of melting point. In addition, the odd–even effect in solid-state FLQY is very small in the reported literature, with only a single-digit difference in most cases.…”

Self-Assembled Cd-MOF Material Supported by a Triazine Skeleton: Stimuli Response to Traces of Nitroaromatics and Amines

“…27−30 Therefore, the scientific community has been attributed to developing detection methods for NACs. 31 At present, the methods for detecting NACs include gas chromatography coupled with mass spectrometry, 32 X-ray imaging and ion mobility spectroscopy, 33,34 Raman spectroscopy, and neutron activation analysis and luminescent sensing detection. 35−37 Among them, the luminescent sensing detection method has received growing attention because of the simple operation and high sensitivity.…”

“…Nitro aromatic compounds (NACs) are widely used in the field of engineering blasting, space applications, explosive forming, and weapon systems. , However, they are highly poisonous and have always been a major safety hazard for human and environmental problems and even threaten national security. − Therefore, the scientific community has been attributed to developing detection methods for NACs . At present, the methods for detecting NACs include gas chromatography coupled with mass spectrometry, X-ray imaging and ion mobility spectroscopy, , Raman spectroscopy, and neutron activation analysis and luminescent sensing detection. − Among them, the luminescent sensing detection method has received growing attention because of the simple operation and high sensitivity. , O -Phenylenediamine (OPD), m -phenylenediamine (MPD), and p -phenylenediamine (PPD), as a class of isomers of primary aromatic amines, are important raw materials or intermediates in the chemical industry .…”