Rapid Quantitative Detection of Brucella melitensis by a Label-Free Impedance Immunosensor Based on a Gold Nanoparticle-Modified Screen-Printed Carbon Electrode

Sensors

Haiyun Wu¹  Yueming Zuo¹  Chuanjin Cui²  Wei Yang¹  Haili Ma³ 

[1] College of Engineering, Shanxi Agriculture University, Taigu 030801, China; E-Mails:;College of Electrical Engineering, Hebei United University, Tangshan 063009, China; E-Mail:;College of Animal Science and Technology, Shanxi Agriculture University, Taigu 030801, China; E-Mail:

关键词: quantitative detection;    Brucella melitensis;    label-free immunosensor;    screen-printed carbon electrode;    gold nanoparticle;   

DOI  :  10.3390/s130708551

来源: mdpi

【 摘 要 】

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 (R_ct) was significantly different due to the binding of Brucella melitensis cells. A linear relationship between the R_ct variation and logarithmic value of the cell concentration was found from 4 × 10⁴ to 4 × 10⁶ CFU/mL in pure culture. The label-free impedance biosensor was able to detect as low as 1 × 10⁴ and 4 × 10⁵ 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.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.