Response Surface Optimization of Nitrogen Doped Rutin Carbon Dots Preparation and Cu2+ Detection
Carbon dots(CDs)are a novel zero-dimensional carbon nanomaterials with special fluores-cent properties and structures.Widely used in analytical testing,biological imaging,electrochemistry,drug delivery and other fields.In order to improve the quantum yield,rutin was used as a single car-bon source and ethylenediamine as the nitrogen source,and carbon dots were prepared by one-step hy-drothermal method.Firstly,through univariate test and the Box-Behnken response surface model,the op-timal process conditions for the preparation of carbon points are predicted.The influence of four fac-tors on fluorescence intensity is reaction temperature>ethylenediamine dosage>reaction time>rutin dos-age.Predicted optimal process conditions:rutin 0.6 g,ethylenediamine 0.6 mL,reaction temperature 200 ℃,reaction time 10 h.Secondly,the morphology and optical properties of carbon dots were charac-terized by X-ray diffractometer,Fourier transform infrared spectrometer,UV/VIS spectrophotometer and fluorescence spectrophotometer.The results show that the carbon dots have the maximum UV absorp-tion peak at 274 nm,and the optimal excitation and emission peaks at 361 nm and 440 nm.The car-bon point is amorphous carbon,and the surface is rich in functional groups such as hydroxyl,amino and carbonyls.Finally,the highly selective carbon dots were used as fluorescent probes to directly de-tect the Cu2+content,and the different concentrations of Cu2+showed a good linear relationship with the fluorescence intensity,and the fitting equation y=0.010 95c+1.024 79,and the lowest detection limit was 0.51 μmol/L.