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Updated: Jun 26, 2026
Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
Published on: June 1, 2011
A simple strategy of probe DNA immobilization by diazotization-coupling on self-assembled 4-aminothiophenol for DNA
Feng Li1, Wei Chen, Pingjun Dong
1Key Laboratory of Eco-Chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
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.
