Facile preparation of orange-emissive carbon dots for the highly selective detection of silver ions

Abstract

The importance of measuring the content of silver ions (Ag⁺) in aqueous solutions and biological samples has increased in recent years due to their very high toxicity to the environment and the human body. Orange-emissive carbon dots (CDs) were simply synthesized through the hydrothermal treatment of p-aminobenzoic acid and p-aminophenol. The obtained CDs display orange fluorescence and stability, including favorable photostability, salt tolerance and water solubility. Significantly, the fluorescence intensity of the CDs was quenched by the addition of Ag⁺via static quenching to form a nonfluorescent complex; thus a highly selective fluorescent method for the determination of Ag⁺ was developed. The present method showed a rapid response and excellent selectivity for Ag⁺ over other metal ions, and the relevant linear range and limit of detection were 5–100 μM and 1.4 μM, respectively. Furthermore, the practicability of this method was validated by the successful determination of Ag⁺ in water samples and a human serum sample. Compared with previous reports, this method showed rapid response and excellent selectivity, which present it as a valuable strategy in environmental protection and biological assays.