Characterization of the designed QD-BRET nanoparticles. Nanoparticles were analyzed with transmission electron microscopy (TEM), dynamic light scattering (DLS), and agarose gel electrophoresis. The TEM image shows the core–shell of the quantum dot nanocrystals averaging 8.2 ± 1.7 (SD, of 20 measurements); while the DLS measured the diameter sizes (n = 5) of the functionalized (32 ± 1.3 nm) vs. non-functionalized (26 ± 1.3 nm) QD-BRET that were significantly different (a, b; P < 0.05; T test). The agarose gel shows differential migration of both nanoparticles, with functionalized aliquots (1+ , 2+ , and 5+) being heavier and migrating slowly than their non-functionalized counterparts (1−, 2−, and 5−). The gel was loaded with various concentrations of nanoparticles (1, 2, and 5 nM/well, equivalent to 3 × 1011, 6 × 1011, and 15 × 1011 nanoparticles, respectively). A 100 base pair (bp) PCR DNA ladder (Lad.) and sperm genomic DNA (gDNA) were loaded alongside for quality control of the gel electrophoresis.