We demonstrate here a novel laboratory experiment for the synthesis of gold nanoparticles (AuNPs) by using a low energy gold-sputtering method together with a modern, green, and biofriendly deep eutectic solvent (DES). The strategy is straightforward, economical, ecofriendly, rapid, and clean. It yields uniform AuNPs of 5 nm in diameter with high reproducibility. Moreover, catalytic applications of AuNPs in DES are shown by studying the conversion of p-nitrophenol to p-aminophenol. Systematic in situ UV-vis spectra are recorded during the catalytic reaction. While the experimental procedures are simple, our laboratory experiments can be applied in a variety of settings depending upon how detailed the instructor requires the depth of the analyses. The laboratory experiments described herein were successfully conducted and evaluated by students with a bachelor degree.