title: Rapid quantitative detection of Brucella melitensis by a label-free impedance immunosensor based on a gold nanoparticle-modified screen-printed carbon electrode.
abstract: A rapid and simple method for quantitative monitoring of Brucella melitensis using electrochemical impedance spectroscopy (EIS) is reported for the first time. The label-free immunosensors were fabricated by immobilizing Brucella melitensis antibody on the surface of gold nanoparticle-modified screen-printed carbon electrodes (GNP-SPCEs). Cyclic voltammetry (CV) and EIS were used to characterize the Brucella melitensis antigen interaction on the surface of GNP-SPCEs with antibody. A general electronic equivalent model of an electrochemical cell was introduced for interpretation of the impedance components of the system. The results showed that the change in electron-transfer resistance (Rct) was significantly different due to the binding of Brucella melitensis cells. A linear relationship between the Rct variation and logarithmic value of the cell concentration was found from 4 × 10(4) to 4 × 10(6) CFU/mL in pure culture. The label-free impedance biosensor was able to detect as low as 1 × 10(4) and 4 × 10(5) CFU/mL of Brucella melitensis in pure culture and milk samples, respectively, in less than 1.5 h. Moreover, a good selectivity versus Escherichia coli O157:H7 and Staphylococcus aureus cells was obtained for our developed immunosensor demonstrating its specificity towards only Brucella melitensis.
authors.affiliation: College of Engineering, Shanxi Agriculture University, Taigu 030801, China. haiyunwu2013@163.com
authors.forename: Haiyun
authors.initials: H
authors.lastname: Wu
authors.forename: Yueming
authors.initials: Y
authors.lastname: Zuo
authors.forename: Chuanjin
authors.initials: C
authors.lastname: Cui
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Haili
authors.initials: H
authors.lastname: Ma
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D055910:Antibodies, Immobilized / Q000737:chemistry / Q000378:metabolism*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D017347:Brucella melitensis / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D002244:Carbon / Q000737:chemistry; D015169:Colony Count, Microbial / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008892:Milk / Q000382:microbiology
chemical_list: D055910:Antibodies, Immobilized; D002244:Carbon; D006046:Gold