title: A simple strategy of probe DNA immobilization by diazotization-coupling on self-assembled 4-aminothiophenol for DNA electrochemical biosensor.
abstract: A novel and simple strategy for fabricating of DNA electrochemical biosensor was developed based on covalent coupling of probe NH(2)-ssDNA (S(1)) on Au electrode that had been functionalized by diazotization of assembled 4-aminothiophenol (4-ATP) monolayer. The thiol group of 4-ATP allowed the stable assembly of 4-ATP monolayer. The following diazotization reaction was directly performed to prepare functional diazo-ATP film for covalent coupling of probe S(1). Remarkably, it was noting that the diazo-ATP provided a surface with high conductibility for electron transfer. The complementary ssDNA was determined by using differential pulse voltammetry. The linear range of the developed biosensor was from 1.57 x 10(-9) to 4.52 x 10(-7)M with a detection limit of 3.26 x 10(-10)M. The fabricated biosensor possessed good selectivity and could be regenerated. The covalent immobilization of probe S(1) by simple diazotization-coupling on self-assembled 4-ATP monolayer could serve as a versatile platform for DNA immobilization and biosensors fabricating.
authors.affiliation: Key Laboratory of Eco-Chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Pingjun
authors.initials: P
authors.lastname: Dong
authors.forename: Shusheng
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D000814:Aniline Compounds / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004247:DNA / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*; D015342:DNA Probes; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D009586:Nitrogen Fixation; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013438:Sulfhydryl Compounds
chemical_list: D000814:Aniline Compounds; D015342:DNA Probes; D013438:Sulfhydryl Compounds; C064316:4-aminothiophenol; D004247:DNA