title: An electrochemical DNA-sensor developed with the use of methylene blue as a redox indicator for the detection of DNA damage induced by endocrine-disrupting compounds.
abstract: An electrochemical biosensor capable of indirect detection of DNA damage induced by any one of the three endocrine-disrupting compounds (EDCs) - bisphenol A (BPA), 4-nonylphenol (NP) and 4-t-octylphenol (OP), has been researched and developed. The methylene blue (MB) dye was used as the redox indicator. The glassy carbon electrode (GCE) was modified by the assembled dsDNA/graphene oxide-chitosan/gold nano-particles to produce a dsDNA/GO-CS/AuNPs/GCE sensor. It was characterized with the use of electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and scanning electron microscopy (SEM) techniques. The loading/release of the MB dye by the dsDNA/GO-CS/AuNPs film was investigated, and the results showed that the process was reversible. Based on this, the sensor was used to measure the difference between the loading capabilities of intact and damaged dsDNA in the films. The sensor was then successfully applied to detect DNA damage electrochemically. The differential pulse voltammetry (DPV) peak current ratio for MB, observed before and after DNA damage, increased linearly in the presence the BPA, NP or OP compounds; the treatment range was 10-60 min, and the respective damage rates were 0.0069, 0.0044 and 0.0031 min(-1), respectively. These results were confirmed by the binding constants: 2.09×10(6) M(-1) (BPA-DNA), 1.28×10(6) M(-1) (NP-DNA) and 9.33×10(5) M(-1) (OP-DNA), all of which were obtained with the use of differential pulse stripping voltammetry (DPSV).
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; College of Chemistry, Nanchang University, Nanchang 330031, China.
authors: Xiaoyun
authors: X
authors: Lin
authors: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; College of Chemistry, Nanchang University, Nanchang 330031, China. Electronic address: ynni@ncu.edu.cn.
authors: Yongnian
authors: Y
authors: Ni
authors: School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4001, Australia. Electronic address: s.kokot@qut.edu.au.
authors: Serge
authors: S
authors: Kokot
mesh_terms: D048271:Chitosan / Q000737:chemistry; D004247:DNA / Q000737:chemistry / Q000235:genetics*; D004249:DNA Damage; D058266:Dielectric Spectroscopy; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D052244:Endocrine Disruptors / Q000633:toxicity*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D015203:Reproducibility of Results
chemical_list: D052244:Endocrine Disruptors; D010087:Oxides; D006046:Gold; D006108:Graphite; D004247:DNA; D048271:Chitosan; D008751:Methylene Blue
keywords: DNA-damage; Electrochemical DNA-sensor; Endocrine-disrupting chemicals; Methylene blue dye