Prussian blue nanoparticle-labeled aptasensing platform on graphene oxide for voltammetric detection of -fetoprotein in hepatocellular carcinoma with target recycling

• Published in: Analyst (London) 2019-08, Vol.144 (16), p.4858-4864
• Main Authors: Zhang, Bei, Ding, Hao, Chen, Qi, Wang, Ting, Zhang, Kunhe
• Format: Article
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c9an01029g

An enzyme-free electrochemical aptasensing platform based on a graphene oxide nanosheet-modified gold-disk electrode was developed for the voltammetric detection of alpha-fetoprotein (AFP) in hepatocellular carcinoma by using a Prussian blue nanoparticle (PBNP)-labeled aptamer. The electroactive PBNP, a typical signal-generation tag, was utilized for the labeling of the aminated AFP aptamer by using covalent conjugation. The electrochemical sensing platform was prepared in a simple manner on the basis of a stacking reaction between the immobilized graphene oxide and the PBNP-labeled AFP aptamer. Upon target AFP introduction, the analyte reacted with the aptamer, thus resulting in the dissociation of the PBNP from the nanosheets. In the presence of DNase I, the newly formed AFP/aptamerPBNP complex was cleaved to release target AFP, which could react again with the aptamer on the nanosheets, thereby causing target recycling. During this process, the cleaved PBNPaptamer was far away from the electrode to decrease the voltammetric signal. Under optimum conditions, the voltammetric peak current of the modified electrode decreased with the increment of the target AFP concentration within the linear range of 0.01300 ng mL 1 at a low detection limit of 6.3 pg mL 1 . The precision and reproducibility of the aptasensing protocol were acceptable (CV: