White Fluorescent Carbon Dots for Specific Fe³⁺ Detection and Imaging Applications

In recent years, carbon dots (CDs) with fluorescence imaging function have been widely used in biomedicine, electronic manufacturing and environmental monitoring. However, monochromatic fluorescence is often limited by the application environment and loses its effectiveness. Here, we carefully designed white fluorescent CDs (WF-CDs) by solvothermal method, which is used for fluorescence imaging applications under different environmental conditions. WF-CDs based on nitrogen doping can produce obvious emission peaks at 640 nm, 490 nm and 400 nm, respectively, corresponding to red, green and blue (RGB) bands in the three primary colors. The full wavelength emission was realized by changing the solvent types and pH values to adjust the emission peak intensity. WF-CDs can accurately detect Fe³⁺ concentration according to fluorescence extinction degree (fluorescence elimination rate reaches 95.34 %). Furthermore, WF-CDs has practical applications in cell-level fluorescence imaging, near-infrared fluorescence imaging and ultraviolet anti-counterfeiting, and has broad application prospects in the fields of nano-medicine and industrial manufacturing.