DNA-Redox Cation Interaction Improves the Sensitivity of an Electrochemical Immunosensor for Protein Detection

Sensors

Ping Li²  Bixia Ge¹  Lily M.-L. Ou²  Zhihui Yao¹  Hua-Zhong Yu² 

[1] Biogate Laboratories Ltd., 110-4238 Lozells Avenue, Burnaby, BC V5A 0C4, Canada; E-Mails:;Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada; E-Mails:

关键词: electrochemical immunoassay;    redox labeling;    signal enhancement;    DNA-cation interaction;    hCG;   

DOI  :  10.3390/s150820543

来源: mdpi

【 摘 要 】

A simple DNA-redox cation interaction enhancement strategy has been developed to improve the sensitivity of electrochemical immunosensors for protein detection. Instead of labeling with fluorophores or redox-active groups, the detection antibodies were tethered with DNA single strands. Based on the electrostatic interaction between redox cations ([Ru(NH₃)₆]³⁺) and negatively charged DNA backbone, enhanced electrochemical signals were obtained. Human chorionic gonadotropin (hCG) detection has been performed as a trial analysis. A linear response range up to the concentration of 25 mIU/mL and a detection limit of 1.25 mIU/mL have been achieved, both are comparable with the ultrasensitive enzyme-linked immunosorbent assay (ELISA) tests. The method also shows great selectivity towards hCG over other hormones such as thyroid stimulating hormone (TSH) and follicle stimulating hormone (FSH). By and large, our approach bears the merits of cost effectiveness and simplicity of instrumentation in comparison with conventional optical detection methods.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.