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 Zn2+, Mn2+, and Cu2+ 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 Zn2+, Mn2+, and Cu2+ through a change in the color of the fluorescence. Upon interaction with Zn2+, the fluorescent color of the GSH‐CDs was transformed from cyan to pink. When exposed to Mn2+ or Cu2+, 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 Zn2+, Mn2+, and Cu2+ were calculated to be 9.64, 3.24, and 1.7 nm, 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 Zn2+, Mn2+, and Cu2+ in real environmental water by GSH‐CDs was also investigated. In addition the GSH‐CDs can be applied in cell imaging.