Related Experiment Video
Updated: Jun 15, 2026
Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
Published on: June 1, 2011
Gold nanoparticles modified electrode via a mercapto-diazoaminobenzene monolayer and its development in DNA
Feng Li1, Yan Feng, Pingjun Dong
1College of Chemistry, Chemical Engineering and Materials Science, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, Ministry of Education, Key Laboratory of Molecular and Nano Probes, Shandong Normal University, Jinan 250014, People's Republic of China.
Abstract:
A novel protocol for the gold nanoparticles (AuNPs) modification on the electrode surface was proposed, which was based on the self-assembly of AuNPs on the mercapto-diazoaminobenzene monolayer modified electrode. The mercapto-diazoaminobenzene monolayer was obtained by covalent immobilization of 4-aminothiophenol (4-ATP) molecules onto another 4-ATP monolayer functionalized gold electrode by diazotization-coupling reaction. The DNA immobilization and hybridization on the AuNPs modified electrode was further investigated. The prepared AuNPs-ATP-diazo-ATP film demonstrated efficient electron transfer ability for the electroactive species toward the electrode surface due to a large conjugated structure of the mercapto-diazoaminobenzene monolayer. The recognition of fabricated electrochemical DNA biosensor toward complementary single-stranded DNA was determined by differential pulse voltammetry with the use of Co(phen)(3)3+ as an electrochemical indicator. A linear detection range for the complementary target DNA was obtained from 3.01 x 10(-10) to 1.32 x 10(-8) M with a detection limit of 9.10 x 10(-11) M. The fabricated biosensor also possessed good selectivity and could be regenerated easily.
