Research On The Determination Of Drugs Based On The Special Properties Of Luminescent Carbon Quantum Dots

As an emerging nanomaterial, carbon quantum dots (CDs) have beenprogressivly developed as a new type of fluorescent probes with its excellent opticalproperties and low toxicity. Currently, CDs have attracted the attention of nationalresearchers and they have been widely used in many areas, such as environmentaltesting, vivo imaging, biological probes, optoelectronic devices and so on. With theprogresses of application of CDs, their synthesis and characterization are sharplydeveloping. However, the factors influencing on the fluorescence properties of CDshave not been widely explored. Several articles about using quantum dots asfluorescent probes to analyze the drugs, nucleic acids, proteins and other biologicalmacromolecules with the characteristics of quantum dots have been reported.However, taking CDs as fluorescent probes for drugs analysis literature are few andfar. This paper attempts to explore the factors influencing on the fluorescenceproperties of CDs and find new fluorescent probes to establish a sensitive andconvenient method for quantitative detection of small molecule drugs. In this paper,fluorescence quenching method is the major research method, UV-visible absorptionspectroscopy, the analyze of sodium chloride particles and the method of temperatureare also used to explore the binding mechanism between CDs and drugs. The maincontents of this paper include the following parts:The water-soluble carbon quantum dots obtained by microwave and the resultsof TEM, UV-visible spectroscopy, fluorescence spectroscopy, infrared spectroscopy,nano particle size analyzer showed that the synthetic method for CDs was simple,rapid and high quantum yield. The paper also preliminarily explored and analysedvarious factors influencing on the fluorescence properties of CDs, such as surfactants,oxidants, reductants, common ions, luminescent molecules, pH, temperature, carbonnanomaterials and so on. In addition, preliminary exploration of the interactionbetween some drugs of the Tetracyclines and Flavonoids and CDs provided a methodfor drug analysis. Based on the fluorescence quenching effect of the microwave heating syntheticwater-soluble carbon quantum dots caused by Curcumin, CDs were evaluated asfluorescence probe for Curcumin detection. In Britton-Robinson buffer solution ofpH4.0, the fluorescence of CDs was quenched significantly after adding Curcumin. Anew determination method was established and the linear range of the method was0.03-3.0μg mL-1with the correlation coefficient of0.9984. The detection limit was4.42×10-10g mL-1, and the analysis results for the synthetic and practical sampleswere satisfactory. The possible mechanism of the interaction between Curcumin andCDs was discussed by UV-visible absorption spectrum, the analysis of the sodiumchloride ion experiments and the relationship between the fluorescence quenchingdegree and temperature.The paper studied the fluorescence quenching effect of Tetracyclinehydrochloride (TC) on the microwave heating synthetic water-soluble carbonquantum dots. In Britton-Robinson buffer solution of pH4.0, the presence of TC ledthe fluorescence intensity of CDs to decrease significantly. Under optimal conditions,the quenched fluorescence intensity was linear with the concentration of TC rangingfrom0.3-30μg mL-1, with the correlation coefficient of0.9991. The detection limitwas2.83×10-9g mL-1, and the analysis results for the synthetic and practical sampleswere satisfactory. The possible mechanism of the interaction between TC and CDswas discussed by UV-visible absorption spectrum, the analysis of the sodium chlorideion experiments and the relationship between the fluorescence quenching degree andtemperature.