| As one of the carbon-based zero-dimensional nanomaterials,carbon dots(CDs)are hold great potential in different fields for their excellent light stability,excellent water solubility,adjustable emission spectrum,low toxicity,good biocompatibility,and easy surface modification.At present,CDs have been widely used in the fields of chemical sensing,biological imaging,drugs and gene delivery,and optoelectronic devices.However,there are still some shortcomings in the research and application of CDs.For example,most CDs can only be detected by single emission wavelength or fluorescence singal.Therefore,it is of great significance to construct ratiometric fluorescent probes based on CDs and prepare fluorescent-colorimetric dual-mode carbon dots for detection of actual samples in bioanalytical chemistry.Based on the previous study,this dissertation has carried out in-depth research based on the design and synthesis and detection application of CDs probe.The following research work have been developed:1.Preparation of CDs/QDs@ZIF-8 and its application in ratiometric detection of ascorbic acidAscorbic acid(AA,Vitamin C),as an important antioxidant,coenzyme in the metabolic process,and essential micronutrients in the diet,plays an important role in human daily life.The accurate and sensitive determination of AA is of great significance for medical diagnosis and food safety.Based on this,CDs/QDs@ZIF-8 composite materials were prepared for the detection of AA by introducing carbon dots and quantum dots into ZIF-8.The composite materials have two emission peaks at 448 nm and 647 nm,respectively.The linear range of this method for ratiometric detection of AA is 5-400?M with a detection limit of 1.5?M.Furthermore,the excellent stability and biocompatibility of the CDs/QDs@ZIF-8 composite materials make it successful for cell imaging.2.Hydrothermal synthesis of carbon dots for fluorescence and colorimetric detection of 2,4,6-trinitrophenol2,4,6-trinitrophenol(TNP)is a nitro aromatic compound with high explosive capacity,its excessive use will cause serious pollution of surface water and soil,posing a huge threat to the environment and human health.Therefore,it is an urgent need to develop a sensor for simple,fast,and sensitive detection of TNP.So,CDs was synthesized by hydrothermal method in this work,which can quickly respond to TNP.The CDs have good water solubility,strong photobleaching resistance ability,excellent salt tolerance and temperature stability.Based on the synergistic effect of static quenching(SQE)and internal filtering effect(IFE),fluorescence and colorimetric dual-mode detection of TNP was achieved.The linear range of TNP in fluorescence mode is 0.1-80?M,and the detection limit is 37 nM in this work.In addition,the CDs can successfully used in determination of TNP in water samples.3.Preparation fluorescence and colorimetric dual-mode carbon dots(DM-CDs)for detection of ClO~-and GSH and biological imagingAccording to reports,oxidative hypochlorite(ClO~-)and antioxidants are closely related to oxidative stress and related diseases.In recent years,many analytical methods have been established by researchers to detect ClO~-and antioxidants.However,most analysis methods are based on single mode detection,so it is meaningful to develop a probe for fluorescence-colorimetric dual-mode detection of ClO~-and antioxidants.Herein,a novel carbon dots(DM-CDs)which can rapidly respond to ClO~-and antioxidants by both fluorescent and colorimetric mode were synthesized.GSH was chosen as model antioxidants to evaluate its detection performance.The fluorescence of DM-CDs can be quenched by ClO~-and then recovered by GSH,so sensitive and accurate detection of ClO~-and GSH can be achieved.Meanwhile,the color variation of this detection process can be directly observed by naked eye and measured quantitatively by UV-Vis spectra.The excellent optical properties of DM-CDs together with their good biocompatibility make it successfully used in cell imaging and detection of intracellular ClO~-and GSH... |
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