Earlier, we have reported the synthesis and thorough physicochemical characterization of AuQC@NLf, where NLf refers to native lactoferrin. In this paper, we show how the clusters are formed in the protein cavity as a function of time. MALDI MS of the protein samples measured as a function of time of incubation show the evolution of the clusters. The mechanism of cluster growth suggests metal ion transfer across molecules which require further study. Copyright © 2011 American Scientific Publishers All rights reserved.