title: Facile electrochemical biosensor based on a new bifunctional probe for label-free detection of CGG trinucleotide repeat.
abstract: We have developed a simple and label-free electrochemical assay to detect CGG trinucleotide repeat. For this purpose, a new bifunctional probe (FecNCD2) was developed, in which a recognition part (naphthyridine carbamate dimmer, NCD) was connected with an electro-active part (ferrocenyl group) using a chain of -CO-NH-CH2-CH2-. The results of circular dichroismic measurements indicated that FecNCD2 exhibited a superior performance for selective binding to CGG trinucleotide repeats compared to a previous bifunctional electrochemical probe connected with shorter linker -CH2- (FecNCD1). Then, the electrochemical properties of FecNCD2 were evaluated and were found to show a good redox response due to the ferrocene moiety. Owing to the high performances of FecNCD2, the label-free electrochemical biosensor for CGG repeats was constructed by immobilizing them onto gold disk electrode and by using FecNCD2 as an electrochemical probe in solution. Further CGG repeats in solution were confirmed to be detectable using the CGG modified biosensor in competitive experiments, i.e., by treating it in test solutions containing FecNCD2 and d(CGG)10 or others. No interference of ct-DNA on the CGG detection was also confirmed with this approach. The strategy should have significant potential for the development of versatile and low-cost biosensor for early diagnosis and treatment of neurodegenerative diseases associated with trinucleotide repeats.
authors.affiliation: College of Chemistry and Chemical Engineer, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University, Youyi Road 368, Wuchang, Wuhan, Hubei 430062, PR China.
authors.forename: Hanping
authors.initials: H
authors.lastname: He
authors.forename: Jingping
authors.initials: J
authors.lastname: Xia
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Peng
authors.forename: Gang
authors.initials: G
authors.lastname: Chang
authors.forename: Xiuhua
authors.initials: X
authors.lastname: Zhang
authors.forename: Yafen
authors.initials: Y
authors.lastname: Wang
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakatani
authors.forename: Zhaowen
authors.initials: Z
authors.lastname: Lou
authors.forename: Shengfu
authors.initials: S
authors.lastname: Wang
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D004247:DNA / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods*; D005296:Ferrous Compounds / Q000737:chemistry; D000075163:Metallocenes; D009287:Naphthyridines / Q000737:chemistry; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D018911:Trinucleotide Repeats
chemical_list: D005296:Ferrous Compounds; D000075163:Metallocenes; D009287:Naphthyridines; D004247:DNA; C427203:calf thymus DNA; C004998:ferrocene
keywords: Electrochemical biosensor; Ferrocenyl modified naphthyridine derivative; Recognition of CGG; Trinucleotide repeat