双重放大酶免疫传感器检测鸡白痢鸡伤寒沙门菌

Enzyme Immunosensor of Double Amplification for Detection of Salmonella pullorum and Salmonella gallinarum

为探求新型鸡白痢鸡伤寒沙门菌快速检测技术,本研究首次利用多壁碳纳米管与离子液体[BMIM]PF6修饰四通道丝网印刷碳电极,制成双重放大信号检测鸡白痢鸡伤寒沙门菌的酶免疫传感器。用原子力显微镜表征其表观形态,循环伏安法监测其电化学特性。结果表明,在优化的检测条件下,免疫电极对目标菌的线性响应范围为103～109 cfu.mL-1,检出限为3.93×102 cfu.mL-1(S/N=3),4℃放置28d后,响应电流为初始值的90.15%,具有良好的稳定性、特异性、重现性和准确性。多壁碳纳米管与离子液体结合制备的鸡白痢鸡伤寒沙门菌酶免疫传感器实现了检测信号的双重放大,检测灵敏度高,离子液体有助于保持酶标抗体的活性,延长免疫电极的有效时间。依据该方法构建的酶免疫传感器为快速检测其它致病菌酶免疫传感器的研究提供了良好的参照模型。

The aim of this work is to seek a new rapid detection technology for Salmonella Dul- lorum and Salmonella gallinarum. In this report, we firstly combined multi-walled carbon nano- tubes with ionic liquid [BMIM]PF6 to modify four-channel screen-printed carbon electrode to pro- pose an enzyme immunosensor with double amplified response signal for detection of Salmonella Dullorum and Salmonella gallinarum. The surface morphology of the modified electrode was characterized by atomic force microscopy, while the electrochemical properties were determined by cyclic vohammetry. The results showed that under the optimal assay conditions, a good linear response occurred in the concentration range of 10^3-10^9 cfu · mL^-1 of Salmonella Dullorum and Salmonella gallinarum, with a low detection limit of 3.93 ×10^2cfu·mL^-1 （S/N= 3）. The sta- bility test of the fabricated immunosensor showed that it remained 90.15 % of its original response signal after storage of 28 days under 4 ℃. The performance evaluation of the proposed immu- nosensor showed that it had high stability, good specificity, acceptable reproducibility and accu- racy. The results demonstrated that the proposed enzyme immunosensor with combination of multi-walled carbon nanotubes and ionic liquid achieved the effect of double amplification of detec- tion signal which enabled it highly sensitive in detection. Ionic liquid was also helpful for maintai-ning bioactivity of enzyme labeled antibody, thereby prolonging effective time of the immune elec- trode. The fabrication of the enzyme immunosensor pursuant to this method provides a good reference model for construction of enzyme immunosensor for rapid detection of other pathogenic bacterium.