In this work, the gold nanoparticles (AuNPs) were synthesized using pulse-modulated radio-frequency atmospheric pressure glow discharge (pm-rf-APGD). By tailoring selected operating parameters of the pm-rf-APGD reaction-discharge system, the experimental conditions for the synthesis of raw-AuNPs with controlled optical and structural properties were found. The colloidal suspension of the size-controlled raw-AuNPs was mixed with an aqueous solution of gelatine and turmeric oil to produce an oil-in-water (O/W) nanoemulsion. AuNPs loaded into the nanoemulsion were characterized using ultraviolet-visible absorption spectrophotometry, dynamic light scattering, scanning electron microscopy supported by energy dispersive X-ray spectroscopy, and transmission electron microscopy equipped with selected area X-ray diffraction. Additionally, attenuated total reflectance Fourier-transform infrared spectroscopy was used to confirm the efficient functionalization of the AuNPs by nanoemulsion component. It was revealed that AuNPs were mostly spherical with an average size of 4.6 +/- 1.0 nm and a face-centered cubic crystal system. The developed O/W nanoemulsion carrying AuNPs was applied towards the human breast cancer cell lines MCF7 and MDA-MB-231. It was found that it exhibited the cytotoxicity towards the breast cancer cells while were non-cytotoxic towards the non-tumour breast cells MCF10A. Moreover, it also inhibited the migration of the invasive cancer breast cells (line MDA-MB-231) and hence, could prevent the breast cancer metastasis.