Objective To study the potential of phytolatex (latex of Jatropha gossypifolia) fabricated gold nanoparticles as promising candidate in sunscreen formulations for enhancement in sun protection factor.

Methods In this study, plant latex was used as reducing and capping agent to synthesize gold nanoparticles. Latex fabricated gold nanoparticles were characterized by different analytical techniques such as UV‐Vis spectroscopy, Fourier transforms infrared spectroscopy, dynamic light scattering, zeta potential, transmission electron microscopy and X‐ray diffraction. Potential of sunscreen preparations containing gold nanoparticles to protect skin from UV radiation was investigated by in vitro sun protection factor analysis. Transmission electron microscopy and UV‐Vis spectroscopy techniques were used to get insight into mechanism by which AuNPs enhance sun protection factor of sunscreen.

Results Monodisperse gold nanoparticles were synthesized using plant latex without need of hazardous chemical reducing and capping agents. Gold nanoparticles showed surface plasmon resonance peak at 550 nm in UV‐Vis spectroscopic study. Gold nanoparticles were spherical and triangular in shape with size range of 30–50 nm. The zeta potential of gold nanoparticles was found to be −9.39 ± 0.19 mV. XRD analysis confirmed face‐centred cubic (fcc) structure of gold nanoparticles. Incorporation of latex synthesized gold nanoparticles (2 and 4 [% w/w]) into commercial sunscreens increased the sun protection factor from 2.43 ± 0.74 to 24.11 ± 0.46% than sunscreen devoid of gold nanoparticles. From UV‐Vis absorption spectroscopy and TEM analysis, it was observed that gold nanoparticles enhance the sun protection factor of commercial sunscreens due to reflection and scattering of UV radiation.