title: DNA-Redox Cation Interaction Improves the Sensitivity of an Electrochemical Immunosensor for Protein Detection.
abstract: 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.
authors: Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada. pingl@sfu.ca.
authors: Ping
authors: P
authors: Li
authors: Biogate Laboratories Ltd., 110-4238 Lozells Avenue, Burnaby, BC V5A 0C4, Canada. bge@sfu.ca.
authors: Bixia
authors: B
authors: Ge
authors: Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada. lilyo@sfu.ca.|Biogate Laboratories Ltd., 110-4238 Lozells Avenue, Burnaby, BC V5A 0C4, Canada. lilyo@sfu.ca.
authors: Lily M-L
authors: LM
authors: Ou
authors: Biogate Laboratories Ltd., 110-4238 Lozells Avenue, Burnaby, BC V5A 0C4, Canada. yaozhihui@hotmail.com.
authors: Zhihui
authors: Z
authors: Yao
authors: Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada. hogan_yu@sfu.ca.
authors: Hua-Zhong
authors: HZ
authors: Yu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002412:Cations; D006063:Chorionic Gonadotropin / Q000652:urine*; D004247:DNA / Q000378:metabolism*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D010084:Oxidation-Reduction; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D002412:Cations; D006063:Chorionic Gonadotropin; D004247:DNA
keywords: DNA-cation interaction; electrochemical immunoassay; hCG; redox labeling; signal enhancement