基于pH响应量子点实现防伪标签的开发及应用

Development and Application of Anti-counterfeit Labels Based on pH-Responsive Carbon Quantum Dots

本研究以木质素磺酸钠及柠檬酸为碳源,采用一步溶剂热法成功制备出木质素磺酸钠/柠檬酸复合碳量子点(CL/GQD)。借助傅里叶变换红外光谱仪、马尔文粒度测定仪、荧光光谱仪、紫外分析仪对其形貌、结构和性能进行了表征,并探究其在防伪领域的应用。实验结果表明,制备的CL/GQD粒径为39.7nm,且其表面含有丰富的官能团。当pH在7~9时,CL/GQD的荧光强度在400nm波长激发下达到了最大值,而当pH在10~12时,其荧光强度在380nm波长激发下取得最大值,上述结果表明CL/GQD具有良好的pH响应。将制得的复合碳量子点直接喷涂到书写纸上得到防伪标签,在自然光和365nm紫外光下可观察到明显的防伪效果,为防伪标签的研究提供了新的思路。

In this study,lignosulfonate/citric acid composite carbon quantum dots(CL/GQD)was prepared from lignosulfonate and citric acid by one-step solvothermal method.The morphology,structure and properties of CL/GQD were characterized by fourier transform infrared spectrometer,malvern particle size analyzer,fluorescence spectrometer and ultraviolet analyzer.Furthermore,the application in the field of anti-counterfeiting was studied.The results showed that the CL/GQD has a diameter of about 39.7nm,and its surface contains abundant functional groups.When the pH is 7~9,the fluorescence intensity of CL/GQD reaches the maximum under excitation at 400nm wavelength,and when the pH is 10~12,it reaches the maximum under excitation at 380nm wavelength.The above results indicated that CL/GQD has a good pH response.The anti-counterfeiting label was obtained by spraying carbon quantum dots directly on writing paper.Obvious anti-counterfeiting effects are observed under natural light and 365nm ultraviolet light,which provides a new idea for the research of anti-counterfeiting labels.