Ultrasensitive detection of toxic cations through changes in the tunnelling current across films of striped nanoparticles

Eun Seon Cho, Jiwon Kim, Baudilio Tejerina, Thomas M. Hermans, Hao Jiang, Hideyuki Nakanishi, Miao Yu, Alexander Z. Patashinski, Sharon C. Glotzer, Francesco Stellacci, Bartosz A. Grzybowski

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111 Citations (Scopus)

Abstract

Although multiple methods have been developed to detect metal cations, only a few offer sensitivities below 1â €‰pM, and many require complicated procedures and sophisticated equipment. Here, we describe a class of simple solid-state sensors for the ultrasensitive detection of heavy-metal cations (notably, an unprecedented attomolar limit for the detection of CH 3 Hg + in both standardized solutions and environmental samples) through changes in the tunnelling current across films of nanoparticles (NPs) protected with striped monolayers of organic ligands. The sensors are also highly selective because of the ligand-shell organization of the NPs. On binding of metal cations, the electronic structure of the molecular bridges between proximal NPs changes, the tunnelling current increases and highly conductive paths ultimately percolate the entire film. The nanoscale heterogeneity of the structure of the film broadens the range of the cation-binding constants, which leads to wide sensitivity ranges (remarkably, over 18 orders of magnitude in CH 3 Hg + concentration).

Original languageEnglish
Pages (from-to)978-985
Number of pages8
JournalNature materials
Volume11
Issue number11
DOIs
Publication statusPublished - 2012 Nov

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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    Cho, E. S., Kim, J., Tejerina, B., Hermans, T. M., Jiang, H., Nakanishi, H., Yu, M., Patashinski, A. Z., Glotzer, S. C., Stellacci, F., & Grzybowski, B. A. (2012). Ultrasensitive detection of toxic cations through changes in the tunnelling current across films of striped nanoparticles. Nature materials, 11(11), 978-985. https://doi.org/10.1038/nmat3406