Highly Sensitive and Discriminative Detection of BTEX in the Vapor Phase: A Film-Based Fluorescent Approach

Abstract

BTEX (benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene) represents a group of volatile organic compounds (VOCs) and constitutes a great threat to human health. However, sensitive, selective, and speedy detection of them on-site and in the vapor phase remains a challenge for years. Herein, we report a film-based fluorescent approach and a conceptual sensor, which shows unprecedented sensitivity, speed, and reversibility to the aromatic hydrocarbons in the vapor phase. In the studies, pentiptycene was employed to produce a nonplanar perylene bisimide (PBI) derivative, P-PBI. The compound was further utilized to fabricate the film. The novelty of the design is the combination of capillary condensation and solvent effect, which is expected to enrich the analytes from vapor phase and shows outputs at the same time. Importantly, the film permits instant response (∼3 s) and real-time identification (<1 min) of benzene and toluene from other aromatic hydrocarbons. The experimental detection limits (DLs) of the six analytes are lower than 9.2, 2.7, 1.9, 0.2, 0.4, and 0.4 ppm, which with the exception of benzene, are significantly lower than the NIOSH recommended long-term exposure limits. More importantly, the film is photochemically stable, and more than 300 repetitive tests showed no observable bleaching. In addition, the sensing is fully reversible. The superior performance of the film device is in support of the assumption that the combination of capillary condensation and solvation effect would constitute an effective way to design high-performance fluorescent films, especially for challenging chemical inert and photoelectronically inactive VOCs.

Naphthyl End‐Capped Terthiophene‐Based Chemiresistive Sensors for Biogenic Amine Detection and Meat Spoilage Monitoring

“…The response and recovery performances of the device were tested with a homemade sensing platform (Figure b). This testing platform is an improvement of the testing platform used in previously reported studies . As an example gas, TMA, was injected ( C =2.11×10 5 ppm, 3 s at a rate of 1.83 mL s −1 ) and there was a concomitant rise in the resistance of the NA‐3T‐NA sensor.…”

“…This testing platform is an improvement of the testing platform used in previously reported studies. [17][18][19][20][21] As an example gas, TMA, was injected (C = 2.11 10 5 ppm, 3s at ar ate of 1.83 mL s À1 )a nd there was ac oncomitant rise in the resistance of the NA-3T-NA sensor.P ump degassing could recover the signal to al evel of 95 %w ithin 23 s. Moreover,t he excellent reusabilityo ft he NA-3T-NA-based sensor was proved by the results from more than 50 cycles of continuous testsw ith TMA (2.11 10 5 ppm) because there had been no observable attenuation in either reversibility or signal intensity (Figure 6c).…”

“…[5,6] About 600 millionp eople get sick every single year, and more than 400 000 peopled ie from unhygienicf oods. [7] Therefore, various techniques, such as quartz crystal microbalance; [8,9] localized surfacep lasmon resonance; [10] radiofrequency identification; [11,12] Raman spectroscopy; [13] and electrochemical, [14,15] fluorescent, [16][17][18][19][20][21][22] and colorimetric sensors, [23,24] have been developed and used for detecting BAs to monitorf ood spoilage. Unfortunately,m ost of these methodsn ot only demands ophisticated instrumentation, but also requiret edious sample preparation and are hard to use on-site.…”

Dendrimer‐Based, High‐Luminescence Conjugated Microporous Polymer Films for Highly Sensitive and Selective Volatile Organic Compound Sensor Arrays

“…Fluorescence‐based detection has aroused increasing public attention due to its potential advantages of low‐cost, real‐time monitoring, simple operation, and easy portability 3. Many efforts have been made to study fluorescence sensors for VOCs,4 among which the fluorescent films as the performance‐determining component in fluorescence sensors are the focus of research 5. In order to fabricate high‐performance fluorescent films for VOC sensing, both the fluorescent materials which have high sensitivity to VOC vapors,6 and the film microstructures which possess favorable VOC diffusion ability are demanded 7.…”

Recent advances in film-based fluorescence sensing

“…还有一些机理如荧光内滤 效应(IFE) [41,42] 、激基缔合物的形成 [43] 、配体-金属能 量转移(LMET) [44] 等, 其详细原理本文不再一一赘述. 近年来, 面对高灵敏探测技术的重大需求, 气相传 感器的创制、研发引起了国际社会的重视, 特别是在 美国政府提出的"电子狗鼻计划""真鼻计划""Cell-All" 和"原子到产品"计划等项目的推动下, 相关研究取得 [27] (网络版彩图) . [49,50] .…”