title: A highly selective and sensitive electrochemical CS-MWCNTs/Au-NPs composite DNA biosensor for Staphylococcus aureus gene sequence detection.
abstract: This paper presents a new electrochemical DNA biosensor constructed using a substrate electrode composed of a novel nanocomposite material prepared using gold nanoparticles (Au-NPs) and multiwalled carbon nanotubes (MWCNTs) and further modified with an Au electrode (AuE), which was used as the substrate electrode. A single-stranded DNA (ssDNA) probe was immobilized on the Au-NPs/CS-MWCNTs/AuE electrode by means of facile gold-thiol affinity, which resulted in hybridization with the target ssDNA sequence. Hybridization reactions were assessed by using the reduction peak current of methylene blue (MB) as an electrochemical indicator. The advantages of the nanomaterials were found to include high surface area, favorable electronic properties, and strong electrocatalytic activity. The amount of ssDNA adsorbed on the electrode surface was increased and the electrochemical response of MB accelerated. The differential pulse voltammetric responses of MB were in line with the specific target ssDNA sequence within the concentration range 1.0×10(-15)-1.0×10(-8)M with the detection limit 3.3×10(-16)M (3σ). In the colony forming unit (CFU) we were able to detect 10CFU mL(-1)of Staphylococcus aureus in the tap water, achieving good discrimination ability between one- and three-base mismatched ssDNA sequences. The polymerase chain reaction (PCR) amplification products of S. aureus nuc gene sequence were also detected with satisfactory results.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Yange
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Xingxing
authors.initials: X
authors.lastname: He
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Min
authors.initials: M
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Zhouping
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address: sxlzzz@jiangnan.edu.cn.
authors.forename: Xiulan
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D061925:Immobilized Nucleic Acids; D008751:Methylene Blue / Q000737:chemistry; D008836:Micrococcal Nuclease / Q000235:genetics; D008892:Milk / Q000382:microbiology; D053758:Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013211:Staphylococcus aureus / Q000235:genetics*; D014871:Water Microbiology
chemical_list: D001426:Bacterial Proteins; D061925:Immobilized Nucleic Acids; D037742:Nanotubes, Carbon; C074002:nuc protein, staphylococcus; D006046:Gold; D008836:Micrococcal Nuclease; D008751:Methylene Blue
keywords: DNA biosensor; Gold nanoparticles; MWCNTs; Methylene blue (MB); Staphylococcus aureus