Construction And Application Of Optical Bioanalytical Method Based On Carbon Dots And Noble Metal Nanoparticles

Carbon is one of basic element of living organisms.In recent years,more and more carbon materials have been used in all facets of daily life.As a kind of carbon material,carbon nano-materials are widely used in biosensing and drug delivery because of their specific properties in optical and chemical aspects.Because the excellent optical properties of carbon nanoparticles,it is play an important role in the field of biological optical analysis,three bio-optical methods are developed in combination with carbon nanoparticles and metal nanoparticles.The optimal detection system for analytes were developed from material synthesis,characterization.The specific systems were constructed as follows:1.Au/Ag core-shell nanoparticles(Au@Ag NPs)and carbon dots(C-dots)were synthesized.Fluorescence of C-dots can be quenched by Au@Ag NPs,the color of Au@Ag NPs solution is yellow,the silver shell of Au@Ag NPs can be etched by hydrogen peroxide(H2O2),the solution colors changes in red.In addition,the quenching effect of Au@Ag NPs on C-dots was significantly reduced,the fluorescence of C-dots recovery.H2O2 can be produced by the oxidation of glucose by glucose oxidase.Therefore,based on changes in the fluorescence intensity and UV absorbance of the system,quantitative analysis of glucose can be achieved.2.An optical analysis sensor for hyaluronidase(HAase)detection was developed based on bio-C-dots and Au NPs.Fluorescence C-dots were synthesized by using Osmanthus fragrans leaves as biomass carbon source.Au NPs with positive charge were synthesized by using chitosan(CS)as modifier(CS@Au NPs).CS@Au NPs agglomerated in the presence of C-dots,the color of the system changed.Due to the negative charge of HA,it can help further stabilize the CS@Au NPs and inhibit the aggregation of CS@Au NPs in presence of C-dots because of the semi-rigid coil conformation and affinity with CS@Au NPs,but the fluorescence of C-dots quenched by CS@Au NP in stable state.But HAase can decompose HA,thus,sensitive determination of HAase can be achieved based on the changes of the fluorescence and UV-Vis signal.3.A series of biomass dual-emission C-dots were synthesized from the leaves of Cinnamomum and used for Al³⁺and water determination.Fluorescence spectrophotometer studies indicated that this type of C-dots has dual emission fluorescence properties and can respond to Al³⁺and H2O by distinctive emission wavelengths due to aggregation-induced emission enhancement(AEE)and solvent effect.The results showed that this type of C-dots have a good linear response to both Al³⁺concentration and H2O content.Furthermore,it has been successfully applied to the analysis of Al³⁺and H2O in water and liquor samples,the result demonstrated that the system has great practical potential.