title: Lable-free quadruple signal amplification strategy for sensitive electrochemical p53 gene biosensing.
abstract: A versatile label-free quadruple signal amplification biosensing platform for p53 gene (target DNA) detection was proposed. The chitosan-graphene (CS-GR) modified electrode with excellent electron transfer ability could provide a large specific surface for high levels of AuNPs-DNA attachment. The large amount of AuNPs could immobilize more capture probes and enhance the electrochemical signal with the excellent electrocatalytic activity. Furthermore, with the assist of N.BstNB I (the nicking endonuclease), target DNA could be reused and more G-quadruplex-hemin DNAzyme could be formed, allowing significant signal amplification in the presence of H2O2. Such strategy can enhance the oxidation-reduction reaction of adsorbed methylene blue (MB) and efficiently improve the sensitivity of the proposed biosensor. The morphologies of materials and the stepwise biosensor were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and cyclic voltammetry (CV). Differential pulse voltammetry (DPV) signals of MB provided quantitative measures of the concentrations of target DNA, with a linear calibration range of 1.0 × 10(-15)-1.0 × 10(-9)M and a detection limit of 3.0 × 10(-16)M. Moreover, the resulting biosensor also exhibited good specificity, acceptable reproducibility and stability, indicating that the present strategy was promising for broad potential application in clinic assay.
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China. Electronic address: wangzonghua@qdu.edu.cn.
authors.forename: Zonghua
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China.
authors.forename: Jianfei
authors.initials: J
authors.lastname: Xia
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China.
authors.forename: Daimin
authors.initials: D
authors.lastname: Song
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China.
authors.forename: Feifei
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China.
authors.forename: Rijun
authors.initials: R
authors.lastname: Gui
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xia
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China.
authors.forename: Sai
authors.initials: S
authors.lastname: Bi
authors.affiliation: Laboratory of Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, College of Chemical Science and Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Collaborative Innovation Center for Marine Biomass Fiber Materials and Textiles, Qingdao University, Qingdao, Shandong 266071, China.
authors.forename: Yanzhi
authors.initials: Y
authors.lastname: Xia
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D016159:Tumor Suppressor Protein p53
keywords: DNA biosensor; Electrochemical; G-quadruplex-hemin DNAzyme; Label-free; Signal amplification; Target recycling