Dendrimer precursors for nanomolar and picomolar real-time surface plasmon resonance/potentiometric chemical nerve agent sensing using electrochemically crosslinked ultrathin films

Prasad Taranekar, Akira Baba, Jin Young Park, Timothy M. Fulghum, Rigoberto Advincula

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Nanomolar detection and specific recognition of pinacolyl methylphosphonate (PMP), a hydrolysis product and an analog of a relatively persistent class of toxic nerve agents, has been achieved. In addition, picomolar sensitivity is observed with methylphosphonic acid (MPA), an end-hydrolysis product for all organophosphate-based nerve agents. This is achieved using a combined surface plasmon resonance (SPR) and potentiometry setup. A modified polyamidoamine (PAMAM) carbazole/Cu2+ dendrimer, which is electrochemically crosslinked on a self-assembled monolayer (SAM) modified Au substrate, is used as an active sensing element for trapping the nerve-agent analogs. The ultrathin films have been used to study the anchoring of nerve agents via non-covalent interactions. The carbazole to amine ratio is optimized to ensure free primary amines are available to interact with the analyte and the Cu2+ ions present in the system, which further enhances the selectivity. The carbazole group on the periphery serves a dual purpose: crosslinking the dendrimers to form a conjugated network film, and generating the potentiometric response. The adsorption kinetics are monitored by using an in situ SPR/potentiometric setup. This technique not only offers a real-time dual detection of highly toxic nerve-agent analogs, but also shows viability for future sensor-device applications.

Original languageEnglish
Pages (from-to)2000-2007
Number of pages8
JournalAdvanced Functional Materials
Volume16
Issue number15
DOIs
Publication statusPublished - 2006 Oct 4
Externally publishedYes

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Condensed Matter Physics
  • Electrochemistry

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