title: Graphene and CdS nanocomposite: a facile interface for construction of DNA-based electrochemical biosensor and its application to the determination of phenformin.
abstract: Graphene/cadmium sulphide (GR-CdS) nanocomposite was synthesized via a low temperature process in aqueous solution. The as-prepared nanocomposite was characterized by scanning electron microscopy, UV-visible spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The impedance analysis indicated that GR-CdS nanocomposite possessed outstanding electrochemical performance for facile electron transfer. When DNA was immobilized on GR-CdS (DNA/GR-CdS) modified electrode, the electrochemical oxidation of guanine and adenine in DNA residue bases was significantly promoted. Due to the interaction of DNA with phenformin, the voltammetric current of guanine or adenine on the DNA/GR-CdS electrode was decreased when phenformin was present in the electrolytic solution. Under optimized conditions, the signal of guanine on DNA/GR-CdS electrode decreased linearly with increasing the concentration of phenformin in the range of 1.0×10(-6)molL(-1) to 1.0×10(-3)molL(-1). The proposed DNA-based electrochemical biosensor was successfully applied to the determination of phenformin in real samples.
authors.affiliation: School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan 430074, PR China.
authors.forename: Lijiao
authors.initials: L
authors.lastname: Zeng
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhu
authors.forename: Jingdong
authors.initials: J
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques; D019187:Cadmium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques; D006108:Graphite / Q000737:chemistry*; D015394:Molecular Structure; D053761:Nanocomposites / Q000737:chemistry*; D010629:Phenformin / Q000032:analysis*; D013440:Sulfides / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D006108:Graphite; D004247:DNA; D010629:Phenformin