Three gold-nanoparticle (AuNP) undergraduate experiment modules that are focused on nanoparticles interfacial phenomena have been developed. Modules 1 and 2 explore the synthesis and characterization of AuNPs of different sizes but with the same total gold mass. These experiments enable students to determine how particle size affects the AuNP optical properties and ligand binding capacities. Module 3 investigates the fundamental mechanism governing organothiol self-assembly onto AuNPs and explores the fate of the sulfur-bounded hydrogen (RS-H) for organothiols on the AuNP surface. A benchtop centrifuge, a UV-vis spectrophotometer, and pH strips are needed. The depth of required chemistry knowledge is appropriate for upper-level chemistry students.