Interaction of a novel starch‐capped CdS quantum dots with human serum albumin and bovine serum albumin

Abstract

A novel CdS quantum dots (QDs) were successfully synthesized in aqueous phase using poly (acrylic acid) grafted onto starch (starch-g-PAA). UV-vis spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) techniques proved that the prepared starch-capped CdS QDs are composed of a CdS core and a polymeric shell with homogeneous size distributions. In order to study its biological behavior, multi-spectroscopic techniques were adopted to investigate their conjugation with human serum albumin (HSA) and bovine serum albumin (BSA) proteins. The recorded UV-vis spectra, cyclic voltammetry (CV) analysis, and the calculated rate of HSA and BSA fluorescence quenching by the QDs demonstrated that the interaction between them leads to the formation of QDs-HSA and QDs-BSA complexes. Moreover, FT-IR spectra showed the conformational changes of the protein in the presence of obtained QDs, indicating the presence of interaction between modified QDs and proteins.

Multifunctional Theranostic Agent of Cu2(OH)PO4 Quantum Dots for Photoacoustic Image-Guided Photothermal/Photodynamic Combination Cancer Therapy

“…FT-IR analysis was then performed to confirm whether the Cu 2 (OH)PO 4 QDs were decorated with PAA ligands. For the Cu 2 (OH)PO 4 QDs, the peaks at 2975 and 2928, 1715, 1585, and 1408 cm −1 were attributed to the C−H stretching vibration mode, the CO stretching vibration mode, and the O−H bending vibration mode, respectively, all of which should come from the PAA ligand 43,44. Compared with the spectrum of pure PAA, the slight shift in the O−H mode might result from the formation of P−OH between Cu 2 (OH)PO 4 and PAA.…”