| In recent years,one of the key tasks of electrogenerated chemiluminescence?ECL?research is to identify new luminophore species.Gold nanoclusters?AuNCs?has become a promising nano-luminophore due to its fascinating performance,such as eco-friendly,high colloidal stability,superior catalytic activity,unusual photophysical properties,and good biocompatibility.Although the fluorescent properties of AuNCs have been widely studied,there are only a few researches about the AuNC-based ECL sensing platform for analytical application.The main reasons probably lie in the weak ECL intensity and the unclear mechanism.Thus,how to obtain a strong and efficient ECL signal of AuNCs becomes the key point to establish AuNC-based ECL sensors.This paper aims to study the ECL mechanism of N-acetyl-L-cysteine-gold nanoclusters?NAC-AuNCs?,explore a new method to prepare a high performance ECL probe,and develop novel ECL sensor based on AuNCs in life analysis.In this paper the main research content is as follows:Chapter I:Study on the ECL properties of NAC-AuNCsThis chapter elucidated the valence states effect on the ECL performance of AuNC.The N-acetyl-L-cysteine-AuNCs?NAC-AuNCs?and the electrochemical reduction method for reducing the AuNCs were firstly employed to this study.Results demonstrate that the electrochemical reduction degree of the AuNCs depended on the reduction potential,and the enhancement of the ECL signals was positively correlated with the reduction degree of AuNCs,which indicated that the valence state of Au plays a vital role in the ECL performance of AuNCs.Furthermore,the proposed method has been successfully extended to the chemical reduction technique and other nanoclusters.Therefore,an excellent AuNC-based ECL method with various advantages,such as simple preparation,less toxicity,high sensitivity and?ECL,and excellent stability,has been proposed.This approach not only opens up a new avenue for designing and developing ECL device from other functional-metal based NCs,but also extends the huge potential application in the ECL sensing.Chapter II:ECL sensor based on high ECL efficiency AuNCs for sensitive determination of GSHOn the basis of the study of the first chapter,in this chapter,a high quantum yield ECL probe AuNCs has been developed by reduction approach,which showed excellent ECL performance in K2S2O8 system.Subsequently,based on the ECL of AuNCs could be quenched greatly by Glutathione?GSH?,a facile method for detecting GSH has been developed.Under optimum conditions,a good linear response to detect GSH ranges from 1.0×10-91.0×10-5 M and 1.0×10-51.0×10-1 M,and the detection limit for GSH was 3.2×10-10 M?S/N=3?.In addition,the presented system exhibited a good selectivity for GSH in the presence of other electrolytes and biomolecules.Moreover,GSH standard recovery in urine samples was also demonstrated.This approach is highly selectivity and reliable,which could be used as a new technique for the detection of GSH.However,the detection results of serum samples were not satisfied.Thus,it is of considerable interest in improving the selectivity and sensitivity of the ECL sensor to extend their applications.Chapter III:High performance ECL sensing platform for GSH detection based on MnO2/AuNCs nanocomposite systemOwing to the resonance energy transfer between AuNCs and MnO2 nanosheets,the ECL intensity of AuNCs could be quenched greatly by MnO2 nanosheet.While,in the presence of GSH,MnO2 nanosheets could be reduced into Mn2+ions,and the ECL signal of AuNCs was recovered.Therefore,in this chapter,an ultrasensitive and high selective ECL sensor for GSH detection has been developed based on this MnO2/AuNCs nanocomposite“Turn Off-On”system.The linear range of the GSH sensing was 1.0×10-11 mol/L1.0×10-1 M,and the detection limit was 2.9×10-12 M.Moreover,the proposal method could detect GSH in human serum samples with excellent recoveries.Together with highly selective,simple,fast,low-cost,and good stability,the method shows good clinical application prospect. |
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