N-doped carbon quantum dots obtained by oleylamine through electrochemical routes: structural study and a proof of concept in the employ as a probe for detection of copper through surface-enhanced ultraviolet absorbance (SEUVA)

This work reports the characterization and application of N-doped carbon quantum dots (CdotN) obtained electrochemically from oleylamine as a copper (II) UV probe. It has been observed that copper salts dissolved in ethanol show a well-defined UV absorption band with an apex at 372 nm. Moreover, CdotN as a complexing agent, promotes emerging surface-enhanced ultraviolet absorbance (SEUVA) events that facilitate copper determination. The characterization of CdotN nanomaterial has been performed by FTIR, UV–Vis, Raman spectroscopy, Atomic force microscopy (AFM), Transmission electron microscopy (TEM), Differential thermal analysis (DTA), and Thermogravimetric analysis (TGA). The detection limit in the standard sample has been assigned as 156 ppb, and the limit of quantification as 312 ppb. The SEUVA technique using CdotN as a probe has been employed to determine copper in real samples present recovery of about 105 and 109%. The copper determination by CdotN did not suffer significantly interfere with other cationic ions or dyes.