Small-sized metal nanoparticles (NPs) are of long standing interest to both magnetism and heterogeneous catalysis. Muon studies of Au NPs encapsulated in 'SBA-15' silica are underway at TRIUMF with the aim of understanding the interaction of Mu(H) with the Au NP system. Evidence from these measurements suggests the formation of an AuMu^+ final state as the Mu atom loses its electron the metal surface. Results suggest faster chemical addition for smaller nanoparticles, consistent with an anticipated enhanced catalytic effect. The Radio Frequency measurements proposed here provide a sensitive method both to confirm the final state species and to directly measure its formation rate. The study should also reveal the magnetic nature of the surface from the RF line widths.