Fast and Selective Luminescent Sensing by Langmuir–Schaeffer Films Based on Controlled Assembly of Perylene Bisimide Modified with A Cyclometalated Au^III Complex

Abstract

Condensed films of functional luminophores dominated by the magnitude and dimensionality of the intermolecular interactions play important roles in sensing performance. However, controlling the molecular assembly and regulating photophysical properties remain challenging. In this study, a new luminophore, ortho‐PBI‐Au, was synthesized by anchoring a cyclometalated alkynyl‐gold(III) unit at the ortho‐position of perylene bisimide. An unprecedented T‐type packing model driven by weak Au‐π interaction and Au‐H bonds was observed, laying foundation for striking properties of the luminophore. Controlled assembly of ortho‐PBI‐Au at the air‐water interface, realized using the classical Langmuir‐Schaeffer technique, afforded the obtained luminescent films with different packing structures. With an optimized film, sensitive, selective, and rapid detection of a hazardous new psychoactive substance, phenylethylamine (PEA), was achieved. The detection limit, response time, and recovery time were < 4 ppb, < 1 s, and < 5 s, respectively, surpassing the performance of the PEA sensors known thus far. The relationship between the characters of films and the sensing performance was systematically examined by grey relational analysis (GRA). The present study suggests that designing novel molecular aggregation with definite adlayer structure is a crucial strategy to enhance the sensing performance, which could be favorable for the film‐based fluorescent sensors.

Integrated Sensing Platform Validated for the Efficient and On-Site Screening of Amine-Containing Illicit Drugs

“…Figure 7c showed the flowchart of the sensor identification process for suspicious personnel, aiming to create a simplified workflow to meet new requirements for body fluid testing in drugfacilitated crime investigations. 30,48 Baseline correction was used to eliminate the background interference signals when the indicator flowed into the sensing platform. A constant I 0 value was obtained as the processed signal.…”

Molecular design and architectonics towards film-based fluorescent sensing

“…27). 82 The micro-morphology of the obtained LS films was thoroughly characterized using microscopy techniques. The sensing experiments indicated that films fabricated on different surface pressures displayed varying responses to phenylethylamine vapor, primarily due to their differences in film thickness and porosity.…”