A fluorescent sensing for glycoproteins based on the FRET between quantum dots and Au nanoparticles

A simple fluorescent probe based on fluorescence resonance energy transfer (FRET) between the glucosamine-Mn-doped ZnS QDs and mercaptophenylboronic acid (MBA)-capped AuNPs was designed for the determination of glycoproteins such as immunoglobulin G (IgG), transferrin (Trf), alpha 1-acid glycoprotein (AGP) and horseradish peroxidase (HRP). The FRET process took place via interaction between the glucosamine on the surface of QDs and boronic acid moieties on AuNPs surface, and resulted in the fluorescence quenched of the Ws. The FRET efficiency from QDs to AuNPs was calculated to be 75.4%. However, the FRET process would be inhibited after glycoproteins were introduced into the QDs-AuNPs system. The stronger interaction between the MBA on the surface of AuNPs and glycoproteins would keep the AuNPs far away from the QDs surface, leading to the fluorescence recovered of the QDs. The as-prepared sensor showed a high sensitivity and selectivity for glycoproteins. The dissociation constants and the detection limits of the selected standard glycoproteins (Trf, HRP, IgG and AGP) were estimated to be around 10(-7) M and 10(-9) M, respectively. Finally, this sensor has been successfully used for the determination of the AGP in serum samples without any_ complicated pretreatment and the recovery was in the range of 70%-105%. (C) 2017 Elsevier B.V. All rights reserved.