The presence of neuritic plaques and amyloid fibrils arising from the misfolding of certain proteins is the principal molecular indicator of neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Methodologies for studying the early stages of amyloid aggregation are rapidly arising to provide a better understanding of the mechanism of fibrillization and cytotoxicity and to identify potential targets for diagnosis and therapy. The method presented here involves the simultaneous use of two different fluorophores, a quinolimide derivative and Nile Blue A. These are capable of interacting with and reporting on the formation of preamyloid aggregates and fibrils of apoferritin through fluorescence resonance energy transfer (FRET), which occurs between them, thus maximizing the contrast in detection and quantitative information of such amyloid species by using multidimensional fluorescence lifetime imaging microscopy (FLIM). This work was supported by grant CTQ2017–85658-R funded by MCIN/AEI/10.13039/501100011033/ FEDER “Una manera de hacer Europa”, and grants PID2019–104366RB-C22 and PID2020–114256RB- I00 funded by MCIN/AEI/10.13039/501100011033. Funding for open access charge: Universidad de Granada / CBUA. We acknowledge the Centro de Instrumentaci ́on Científica (CIC) of Universidad de Granada for use of the TEM facilities. ́A.R.-A. thanks the Spanish Ministerio de Educación y Formación Profesional for a FPU Ph.D. studentshi