کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6472558 | 1424135 | 2016 | 9 صفحه PDF | دانلود رایگان |
An effective way to prepare the reagentless electrochemical microbial biosensor has been developed. First, the mediator thionine (TH) is wrapped on the surface of E. coli (E. coli@TH) through the simple electrostatic interaction, which makes E. coli and TH closely together and therefore shortens the electron transfer distance between the electroactive centers and the electrode. Then, E. coli@TH together with chitosan (CHI)-entrapped carbon nanodots (CNDs)are immobilized onto the glassy carbon electrode (GCE) surfaces to form the reagentless electrochemical microbial biosensor (CHI-CNDs-E. coli@TH), in which the CNDs are used to improve the conductivity of the modified electrode, and further enhance the electron transfer from E. coli to the electrode. The reagentless CHI-CNDs-E. coli@TH biosensor is finally used to evaluate the toxicity of four heavy metal ions (Cd2+, Cu2+, Pb2+, Zn2+) and three real wastewater samples, showing good performance in the evaluation of wastewater toxicity compared to other reported methods. This work opens up a new way for the preparation of reagentless electrodes, making it possible for electrochemical microbial biosensors to be equipped and realize on-line detection.
Journal: Electrochimica Acta - Volume 222, 20 December 2016, Pages 303-311