High-Performance Ketone Sensing in Vapor Phase Enabled by o‑Carborane-Modified Cyclometalated Alkynyl-Gold(III) Complex-Based Fluorescent Films

Development of high-performance, low-power-consumption, small-sized detectors is a key issue for fabricating specific miniaturized chromatographs (GCs). Herein, we report, for the first-time, utilization of a film-based fluorescent sensor as a GC detector. In the studies, we designed a new o-carborane derivative of a known cyclometalated alkynyl-gold­(III) complex, Au-CB. Unlike the parent gold­(III) complex, the newly synthesized Au-CB depicted a remarkable aggregation-induced emission (AIE) property, enabling fabrication of a fluorescent film. The film emission is highly sensitive to the presence of ketones such as acetone, 2-pentanone, 3-pentanone, cyclopentanone, etc., in the air. It was demonstrated that the sensing performance of the film could be further improved by changing the film from a planar structure to a tubular one. Via combination with an earlier reported homemade sensory device, a conceptual film-based fluorescent sensor was developed, which demonstrated instant and fully reversible response to the ketones. The experimental detection limits for cyclohexanone and acetone could be lower than 0.08 and 13.0 ppm, respectively. Moreover, the sensor is super stable, as 24 h continuous illumination resulted in less than 1.0% reduction of the fluorescence emission, 50 successive sensings showed no observable decay in the performance, and more than 1 year of storage had no effect upon the property. Further studies demonstrated that the film sensor could be used as a GC detector with performance comparable to the commercial flame ionization detector (FID), which lays the foundation for future applications in specific miniaturized GCs because of its merits in size, power consumption, carrier gas, etc.