A Quantitative Bacteria Monitoring and Killing Platform Based on Electron Transfer from Bacteria to a Semiconductor

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Original languageEnglish
Article number2003616
Number of pages9
Journal / PublicationAdvanced Materials
Issue number39
Online published19 Aug 2020
Publication statusPublished - 1 Oct 2020


A platform with both bacteria killing and sensing capabilities is crucial for monitoring the entire bacteria-related process on biomaterials and biomedical devices. Electron transfer (ET) between the bacteria and a Au-loaded semiconductor (ZnO) is observed to be the primary factor for effective bacteria sensing and fast bacteria killing. The electrons produce a saturation current that varies linearly with the bacteria number, semi-logarithmically, with R2 of 0.98825, thus providing an excellent tool to count bacteria quantitatively in real-time. Furthermore, ET leads to continuous electron loss killing of about 80% of Escherichia coli in only 1 h without light. The modularity and extendability of this ET-based platform are also demonstrated by the excellent results obtained from other semiconductor/substrate systems and the stability is confirmed by recycling tests. The underlying mechanism for the dual functions is not due to conventional attributed Zn2+ leaching or photocatalysis but instead electrical interactions upon direct contact. The results reveal the capability of real-time detection of bacteria based on ET while providing information about the antibacterial behavior of ZnO-based materials especially in the early stage. The concept can be readily incorporated into the design of smart and miniaturized devices that can sense and kill bacteria simultaneously.

Research Area(s)

  • antibacterial activity, Au nanoparticles, bacteria sensing, electron transfer, zinc oxide nanorods

Citation Format(s)