Effective Determination of Zn2+, Mn2+, and Cu2+ Simultaneously By Using Dual‐Emissive Carbon Dots as Colorimetric Fluorescent Probe

Dual‐emissive fluorescent glutathione carbon dots (GSH‐CDs) have been synthesized by a green hydrothermal method and used as a colorimetric fluorescent probe for the multi‐detection of Zn 2+ , Mn 2+ , and Cu 2+ individually or simultaneously. The GSH‐CDs exhibit dual fluorescence emission at 460 and 683 nm, which results in cyan fluorescence emission under UV light. The dual‐emissive GSH‐CDs can be used as a multifunctional colorimetric fluorescent nanoprobe for precise and quantitative detection of Zn 2+ , Mn 2+ , and Cu 2+ through a change in the color of the fluorescence. Upon interaction with Zn 2+ , the fluorescent color of the GSH‐CDs was transformed from cyan to pink. When exposed to Mn 2+ or Cu 2+ , the fluorescence color was transformed from cyan to blue. When the three ions were present simultaneously, the cyan fluorescence emission changed to a nattier blue. The minimum limits of detection (LODs) for Zn 2+ , Mn 2+ , and Cu 2+ were calculated to be 9.64, 3.24, and 1.7 n m , respectively. As far as we know, this is the first report of the use of dual‐emissive carbon dots for the multi‐detection of heavy‐metal ions. Moreover, the multi‐detection of Zn 2+ , Mn 2+ , and Cu 2+ in real environmental water by GSH‐CDs was also investigated. In addition the GSH‐CDs can be applied in cell imaging.