Direct, rapid synthesis of water-dispersed copper nanoparticles and their surface-enhanced Raman scattering properties

•Water-dispersed copper nanoparticles are rapidly synthesized under air atmosphere.•Sodium hyposulphite works as reducing agent and gelatin as capping agent.•High-purity copper nanoparticles are relies on the amount of NaOH and gelatin.•The copper nanoparticles exhibit an excellent SERS activity.

A facile synthetic method for monodisperse copper nanoparticles (CuNPs) has been reported, in which sodium hyposulphite works as reducing agent and gelatin serves as capping agent. Water-dispersed CuNPs have been produced without any protective atmosphere at room temperature. The as-prepared samples are characterized by ultraviolet-visible spectroscopy, transmission electron microscopy, X-ray diffraction and Raman spectra. The results show that the quasi-spheres and phase-pure crystalline CuNPs with a diameter of 32 ± 3 nm can be quickly obtained by adjusting the amount of NaOH solution and quantity of gelatin. The present work suggests a great potential of using obtained CuNPs colloidal as an efficient substrate for surface-enhanced Raman scattering signals.

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