| As one of the research hotspots in the field of chemistry and materials,aggregation-induced luminescent materials have been widely used in sensing analysis,bioimaging,and disease diagnosis and treatment.Due to the unique aurophilic interactions,the nanomaterials formed by self-assembly of gold(Ⅰ)complexes not only possess various morphological nanostructures,but also generally exhibit aggregation-induced phosphorescence emission properties,which makes them show promising application prospects in the field of constructing highperformance nanoluminescent sensors.Starting from the preparation of gold(Ⅰ)nano materials and the study of their optical properties,three kinds of luminescent nanosensors are constructed by using gold(Ⅰ)nanomaterials to realize the detection of various target analytes.The works are presented as following:1.Aggregation-induced phosphorescence-active gold(Ⅰ)-cysteine(Au(Ⅰ)-Cys)nanocomplexes for construction of ferric-specific quenching nanosensor:Au(Ⅰ)Cys nanocomplexes with nanofibers morphology were prepared by using watersoluble ligand cysteine.The Au(Ⅰ)-Cys nanocomplexes exhibited aggregationinduced phosphorescence emission with an emission peak at 590 nm.In addition,the photoluminescence of Au(Ⅰ)-Cys nanocomplexes could be quenched specifically by ferric ions over the other common 18 metal ions.Further transmission electron microscopy characterizations revealed that the quenching process was accompanied by the ferric-specific dissociation of Au(Ⅰ)-Cys nanofibers.These observations have enabled the development of a water-soluble aggregation-induced phosphorescence-active "turn-off" nanosensor based on Au(Ⅰ)nanocomplexes for selective and sensitive detection of ferric ions.This study indicates that specific quenching and disassociation of AIP-active nanocomplexes might be a promising route for development of novel luminescent nanosensors.2.Strongly phosphorescent and water-soluble gold(Ⅰ)-silver(Ⅰ)-cysteine(Au(Ⅰ)-Ag(Ⅰ)-Cys)nanoplatelets for intracellular hypochlorite detection:using heteroatoms doping strategy,with the cysteine-assisted synthesis approach,the Ag(Ⅰ)doping to the Au(Ⅰ)complexes could form the supramolecular organometallic nanoplatelets.Inside,the Au(Ⅰ)-Ag(Ⅰ)metallophilic interactions showing an Au to Ag charge transfer property were formed,thereby enhancing the photoluminescence intensity via the charge transfer from the bioligand’s S to the metal-metal center.The quantum yield was measured to show a maximum 1 6-fold enhancement(i.e.,from 0.85 to 13.8%).In the presence of ClO-,the metalthiolate ligand structure of the as-synthesized Au(I)-Ag(I)-Cys nanoplatelets could be oxidatively damaged,causing the photoluminescence quenching,thereby producing the effect of biorecognition towards ClO-anions.The ClO-induced photoluminescence quenching was specific over the other typical reactive oxygen species and the potential interfering substances in biological samples.In addition,the Au(Ⅰ)-Ag(Ⅰ)-Cys nanoplatelets had good biocompatibility.Thus,they could be further developed as a biosensor for detecting endogenous ClO-anions in living cells.3.A luminescent nanosensor based on inner filter effect(IFE)was constructed using bimetallic nanoplatelets(AuCu NPs)for label-free,sensitive and specific detection of sarcosine:the AuCu NPs were formed by the cysteine-induced coreduction reaction,which displayed bright PL with an emission peak at 560 nm.By integrating the AuCu NPs with p-phenylenediamine(PPD)oxidation reaction,an IFE-based sensor for sarcosine detection was constructed.In this method,sarcosine is oxidized under the catalysis of sarcosine oxidase(SOx)to yield H2O2.The latter further oxidizes PPD to form 2,5-diamino-N,N’-bis(p-aminophenyl)-1,4benzoquinone di-imine(PPDox)in the presence of horseradish peroxidase(HRP).The UV-vis absorption spectrum of the PPDox can overlap well with the excitation and emission spectra of the AuCu NPs,resulting in the efficient quenching of the AuCu NPs via the IFE effect.Therefore,this IFE-based AuCu NPs/SOx/PPD/HRP sensing platform can be used for highly sensitive and specific sensing of sarcosine.Furthermore,this IFE-based sensing platform could be developed into a paperbased biosensor for simple,instrument-free,and visual detection of sarcosine. |
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