Donkey anti rabbit alex 594 secondary antibody

Hydroxylated graphene quantum dots (GQDs) (1 mg/mL, purity >80%) were purchased from ACS Material. Lyophilized human beta-amyloid (1–42) (Aβ₄₂ monomer, DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA; HPLC purity≥95%^{48 (link)}) was purchased from AnaSpec. Oligomer A11 polyclonal antibody was obtained from Invitrogen. Donkey anti-rabbit Alex 594 secondary antibody and phalloidin-iFluor 488 were purchased from Abcam. OxiSelect^™ intracellular ROS detection kit was obtained from Cell Biolabs. All sample solutions were prepared in Milli-Q water and the solvents used were of analytical grade.

1.4×10⁵ SH-SY5Y cells/well were seeded onto 8-well chamber slide (μ-Slide, Ibidi) and cultured overnight in a humidified, 37 °C, 5% CO₂ incubator. Aβ oligomers (20 μM) or ultrasmall MoS₂ QDs (10 and 100 μM) were incubated with cells for 3 h. Cell culture media were used as negative control. Cells were gently washed twice with phosphate-buffered saline (PBS), and 4% of paraformaldehyde was added to fix the cells at room temperature for 15 min. After that, immunofluorescent staining was performed to reveal the distribution and organization of Aβ-o and actin filaments. Primary rabbit anti-oligomer polyclonal antibody (Invitrogen, 1:400) was incubated with the cells at 4 °C overnight, then donkey anti-rabbit Alex 594 secondary antibody (Abcam, 1:500) was used to conjugate with the primary antibody at room temperature for 2 h. Actin filaments were labelled with phalloidin-iFluor 488 (Abcam, 1:1000) at the same time. Then the cells were washed with PBS and further stained by Hoechst 33342 (Sigma, 2 μg/mL) for 5 min. After washing twice with PBS, the cells were observed with a Leica SP8 inverted confocal fluorescence microscope.