Amyloid-β (Aβ), a short peptide which self-assembles into large aggregates, was observed in the gray matter of Alzheimer’s patients. The aggregates in oligomeric and fibrillar forms were proven to be toxic to our brain. Based on this, many groups have taken on the task of investigating the aggregation process of Aβ. Previous work in our lab has shown that metal complexes can be used as a new family of photoluminescence probes for the detection of Aβ aggregates. More specifically, Dr. Amir Aliyan in our research group showed that [Re(CO)3(dppz)(Py)]+ exhibits a secondary light-switching response in the presence of Aβ fibrils upon UV irradiation, and at the same time performs oxidation on Aβ fibrils. This thesis focuses on investigating the interactions between Aβ and rhenium complexes and also probing Aβ oligomerization using ruthenium complexes. Chapter 1 is an introduction of the photoluminescence probes for the detection of Aβ aggregates, and the previous work of our lab on the metal complexes. Chapter 2 details the interactions between Aβ fibrils and [Re(CO)3(dppz)(Py)]+. Job plot and binding assay were used to determine the dissociation constant Kd as 4.2 ± 0.6 μM. Molecular dynamics simulations were used to propose a binding site for [Re(CO)3(dppz)(Py)]+ on Aβ fibrils is at a hydrophobic cleft between Val18 and Phe20. Due to the fact that Aβ fibrils are oxidized by [Re(CO)3(dppz)(Py)]+ after UV irradiation, the binding site was studied using the oxidation site as a chemical footprint. In addition, the study of the photooxidation of Aβ monomers showed that after UV irradiation His13 and Tyr10 are also prone to be oxidized by [Re(CO)3(dppz)(Py)]+. In order to further study the secondary light-switching behavior of [Re(CO)3(dppz)(Py)]+, functional groups were used to simulate the amino acids of Aβ and we found the photoluminescence of [Re(CO)3(dppz)(Py)]+ was enhanced in the presence of imidazole and dimethyl sulfide in SDS solutions but not in buffer. In addition, the quantum yield of singlet oxygen produced by [Re(CO)3(dppz)(Py)]+ upon UV irradiation, power flux of the irradiation source, and the quantum yields of photooxidation were determined. In chapter 3, I reported using photoluminescence anisotropy of [Ru(bpy)2(dpqp)]2+ for the detection of Aβ oligomerization. Aβ oligomers are believed to form immediately following monomers, however they are invisible to fluorescence sensors, such as Thioflavin T. Given that photoluminescence anisotropy is sensitive to the rotational correlation time of molecules, it is useful for monitoring the formation of biomolecule aggregates. We found that Aβ oligomers start to form from time zero with a steady increase in anisotropy that plateaus after 48 hours. The real-time monitoring of Aβ oligomers is of great importance for understanding the kinetics of aggregation, the forces that bring peptides together and study their inhibition. The formation of Aβ oligomers was supported by Western Blot analysis.