Construction And Detection Of Sensing Array Based On Gold Nanoclusters

Gram-positive and negative bacteria(G-and G+ bacteria)and amino acid identification are of considerable positive significance for diagnosis and treatment in clinical medicine because diseases brought on by bacteria and amino acids seriously endanger human health.With the development of nanotechnology,researchers have developed a variety of functionalized AuNCs,with unique fluorescent properties,which are widely disseminated in biochemical detection,bioimaging and antibacterial applications.AuNCs own small size effect which exhibit excellent fluorescence characteristics and stability.It is often employed as a sensing unit for biochemical substance detection,disease diagnosis and other fields.However,a single sensor can detect only one specific substance,greatly limiting the range of sensor applications.An developing technique to recognize a variety of bacteria and amino acids,optical sensor arrays,efficiently resolves this issue.Therefore,it is an intriguing study to build new fluorescent sensor arrays to detect G-and G+ bacteria as well as amino acids.To address the above issues,the research of this paper is as follows:Five different ligand-modified AuNCs were synthesized.The five AuNCs have similar structures but different fluorescence intensities.A series of characterizations,including spectra,electron microscopy and particle size,were carried out to examine their stability,fluorescence quantum yields were measured,and their biocompatibility was investigated.An overall evaluation of the synthesized AuNCs was performed.Fluorescence sensing arrays were constructed using five different ligand-modified AuNCs.Based on the differences in the surface material of G-and G+ bacteria interacting differently with the surface ligands of AuNCs,different degrees of aggregation of AuNCs occurred,which caused changes in the fluorescence intensity of AuNCs and generated unique fluorescence response patterns,thus enabling the classification and identification of bacteria at low concentrations.In addition,bacteria in bovine serum and urine samples were classified and identified.A pH-modulated AuNCs-based sensing array was designed for amino acid classification and identification.The p H environment for the reaction of amino acids with AuNCs was investigated,and experiments demonstrated that the classification and recognition of 17 amino acids could be achieved at a p H of 8.Since the surface ligands of AuNCs contain idimethylamino groups containing 2 methyl groups,which enhance the hydrophobicity of AuNCs,their binding affinity to hydrophobic amino acids is stronger than that of hydrophilic amino acids,causing a change in the fluorescence intensity of AuNCs.Based on this difference,the classification and recognition of amino acids was achieved.In summary,this paper successfully classified and identified low concentration of bacteria and amino acids based on fluorescence sensing arrays constructed by AuNCs.In this study,fresh approaches and concepts for biochemical identification by AuNCs in sensor arrays are presented.