Spectral and time-resolved photoluminescence of human platelets doped with platinum nanoparticles

Abstract

This paper describes a detailed study of spectral and time-resolved photoprocesses in human platelets and their complexes with platinum (Pt) nanoparticles (NPs). Fluorescence, quantum yield, and platelet amino acid lifetime changes in the presence and without femtosecond ablated platinum NPs have been studied. Fluorescence spectroscopy analysis of main fluorescent amino acids and their residues (tyrosine (Tyr), tryptophan (Trp), and phenylalanine (Phe)) belonging to the platelet membrane have been performed. The possibility of energy transfer between Pt NPs and the platelet membrane has been revealed. Förster Resonance Energy Transfer (FRET) model was used to perform the quantitative evaluation of energy transfer parameters. The prospects of Pt NPs usage deals with quenching-based sensing for pathology's based on platelet conformations as cardiovascular diseases have been demonstrated.

Fig 1. The schematic diagram of FDTD simulation process.

Fig 2. FDTD model of Pt NPs with 40 nm radii for λ = 251 nm excitation wavelength.

Fig 3. FDTD model of Pt NPs with 50 nm radii for λ = 251 nm excitation wavelength.

Fig 4. FDTD model of Pt NPs with 50 nm radii for λ = 251 nm excitation wavelength.

Fig 5. Pt NPs plasmon absorption band and NPs size distribution (inset).

Fig 6. FDTD Pt NPs dimer simulation results.

Fig 7. Absorption spectra of Pt NPs (blue dashed line), platelets (blue solid line), Trp (green solid line), Tyr (red solid line) and Phe (purple solid line) fluorescence spectra.

Fig 8. Results of Gauss modeling for platelet experimental fluorescence curve (dark blue line) including: Free Trp curve (blue line), Trp on the platelet membrane (green line) and Trp buried/masked Tyr residue (red solid line).

Fig 9. Fluorescence intensity of platelets without (blue line) and with (red line) Pt NPs.

Fig 10. Quantum yield experimental data for platelet samples without Pt NPs (blue columns) and with Pt NPs (red columns).

Fig 11. Fluorescence lifetime experimental data for platelet samples without Pt NPs (blue columns) and with Pt NPs (red columns).