Coordinate bonding-induced emission of gold-glutathione complex for sensitive detection of aluminum species

Luminescent materials with aggregation-induced emission (AIE) have been widely used in chemosensors and biosensors based on signal change induced by physical aggregation of AIEgens. In this work, a novel coordinate bonding-induced emission (BIE) phenomenon of gold-glutathione complex was proposed and identified, and this specific coordinate BIE was further utilized to develop signal-enhanced methods for quantification of aluminum species including aluminum cation and polyoxocation AlO 4 Al 12 (OH) 24 (H 2 O) 12 7+ . Gold-glutathione (Au-GSH) complex has shown significant aggregation-induced emission characteristic, and it can sensitively respond to multiple external stimuli such as solvent polarity and pH via an emission-enhancing fashion. It is found that the introduction of aluminum cation to Au-GSH complex is able to more greatly enhance the luminescence through a coordinate bonding-induced emission process, and this BIE behavior is attributed to strong force induced by coordination reaction between glutathione ligands and aluminum cation. In comparison with AIE process, coordinate BIE process was shown to be a more efficient way to enhance the emission. This BIE property of Au-GSH complex was employed to measure aluminum cation and polyoxocation Al 13 with good selectivity. This work provides a new coordinate bonding-induced emission phenomenon, and gives a demonstration of designing chemosensors for metal cations based on coordinate BIE process.