Study On The New Methods For Spectrofluorimetry Determination Of D-Penicillamine,Glyphosate And Sunset Yellowvia Carbon Dots

Carbon quantum dots?CDs?,as a noval nanomaterials,have shown great promise for bioimaging and biomedical applications in recent years due to their diversity of synthetic methods,excellent water dispersibility,chemical and photo stability and unique optical properties.Herein,three kinds of CDs which concluding nitrogen,oxygen are synthesized by hydrothermal,The absorption and fluorescent spectra of CDs are systematically studied.As a consequence,new and simple spectrofluorimetric assays are proposed and validated for the qualitative and quantitative determination of D-Penicillamine,Glyphosate and Sunset Yellow in different real samples.The detailed results are summarized as follows:A fluorescence switch sensor used for D-Penicillamine sensing and logic gate based on the fluorescence recovery of carbon dotsA specific and sensitive fluorometric method based on the Carbon dots?CDs?probe which show unique optical properties is proposed for the determination of DPenicillamine?D-PA?in human serum samples with satisfactory results.The fluorescence of CDs decreased apparently in the presence of mercury ion(Hg²⁺),Similarly,the addition of D-Penicillamine?D-PA?resulted in efficient fluorescence recovery of the CDs due to the strong affinity between Hg²⁺ and D-PA.Herein,this phenomenon has been exploited to design an “AND” logic gate and specific fluorescence switch sensor for sensitively sensing D-PA for the first time.Furthermore,the CDs possesses bright blue fluorescence with the maximum excitation and emission wavelength at 358 nm and 442 nm,respectively.Thus,after the experimental conditions are optimized,the linear range for detection PA is 2.0²4.0 ?mol·L^-1,with correlation coefficient and detection limit is R2 = 0.998,0.6 ?mol·L^-1,respectively.Moreover,the proposed method is not only expected to be come a potential tool for the fast response of D-PA but also possesses the potential for practical application.Fluorescent carbon dots for glyphosate determination based on fluorescence resonance energy transfer and logic gate operationHerein,a novel method based on fluorescence resonance energy transfer?FRET?between carbon dots?CDs?and glyphosate?Gly?was designed for Gly detection.CDs were synthesized via a facile and one-step hydrothermal method using citric acid and Tris.The CDs possessed strong blue fluorescence and excitation wavelength-dependent emission behavior with the maximum excitation and emission wavelength at 340 nm and 410 nm,respectively.However,the presence of glyphosate could effectively quench the fluorescence intensity of the CDs through FRET and this phenomenon has been exploited to design an “AND” logic gate for sensitively sensing Gly for the first time.Furthermore,the proposed method has been successfully utilized to detect glyphosate in water samples with satisfactory results.The detection limit for glyphosate was 0.6 ?mol·L^-1?3?/k?,with the linear range of 0.02².0 ?mol·L^-1.This is a promising approach for rapid screening of glyphosate in environmental water samples without using any costly instruments.Determination of sunset yellow in soft drinks based on fluorescence quenching of carbon dotsFluorescent carbon dots was prepared by heating N-?2-hydroxyethyl?ethylene diaminetriacetic acid in air.The carbon dots were not only highly soluble in water but also uniform in size,and possessed strong blue fluorescence and excitation wavelengthdependent emission properties with the maximum excitation and emission wavelength at 366 nm and 423 nm,respectively.Food colorant sunset yellow whose excitation and emission wavelength at 303 nm and 430 nm could selectively quench the fluorescence of carbon dots,efficient fluorescent resonance energy transfer between the carbon dots and sunset yellow is achieved.This was exploited to design a method for the determination of sunset yellow in the concentration range from 0.3 to 8.0 ?mol·L^-1,with a limit of detection?3?/k?of 79.6 nmol·L^-1.Furthermore the fluorimetric detection method was established and validated for sunset yellow in soft drinks samples with satisfactory results.