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7682663 
Journal Article 
Ultrathin Luminescence Film Based on Gold Nanoclusters with Aggregation-Induced Emission 
Guan Weijiang; Zhou Wenjuan; Lu Chao; , 
2016 
Yes 
Huaxue Xuebao / Acta Chemica Sinica
ISSN: 0567-7351 
SCIENCE PRESS 
BEIJING 
74 
11 
929-934 
Chinese 
WOS:000392462100011 
Solution-based fluorescent probes usually need to be fabricated into fluorescent films for device application. The fabricated fluorescent films can have not only the original advantages of probes (e.g., high sensitivity and selectivity) but also several unique properties, such as tunable shape and size, recycling, non-invasion, good stability and portability, and real-time detection. However, the sensitivity of fluorescent films is often reduced by the aggregation-caused quenching (ACQ) effect during the film formation: fluorophores with high concentration inherently tend to aggregate through intermolecular pi-pi interactions. Moreover, the sensing performances of the fluorescent film are significantly influenced by the diffusion rate of analytes: the thicker the films, the slower the response time towards target molecules. Therefore, aggregation-induced emission (AIE) materials are urgently needed to be developed to overcome these shortcomings. On the other hand, excellent photostability could be better for the practical applications in the integrated sensor devices. However, most of the present AIEgens are pi-conjugated organic molecules with poor ability against photobleaching. Interestingly, several fluorescent gold nanoclusters (AuNCs) with higher photostability were discovered to have AIE property. In this work, two kinds of negatively-charged fluorescent AuNCs were selected: bovine serum albumin capped AuNCs (BSA-AuNCs) and AIE-active glutathione capped AuNCs (GSH-AuNCs). Quartz glass slides were alternately dipped into a poly(allylamine) (PAH) solution and AuNCs solutions to fabricate GSH-AuNCs/PAH (yellow-emitting) and BSA-AuNCs/PAH (red-emitting) fluorescent ultrathin films, respectively. As expected, the photoluminescence quantum yield of GSH-AuNCs is two-fold higher in GSH-AuNCs/PAH ultrathin films than in solution. The fluorescence of (GSH-AuNCs/PAH)(5) ultrathin film could be quenched effectively by 2,4,6-trinitrotoluene (TNT) in 10 min, while the fluorescence intensity of (BSA-AuNCs/PAH)(25) ultrathin film remain almost unchanged. Based on this phenomenon, a novel ratio fluorescence sensing system was constructed by using (BSA-AuNCs/PAH)(25) ultrathin film as control and (GSH-AuNCs/PAH)(5) ultrathin film as the detection unit. The fluorescence intensity ratios (I-565/I-620) have a linear relationship with the log concentrations of TNT in the range of 10(-6)similar to 10(-9) mol/L with detection limit of 1.0 X 10(-10) mol/L. 
Aggregation-induced emission; Explosive; Gold nanocluster; Layer-by-layer assembly; Luminescent film