Selective detection of nitroexplosives using molecular recognition within self-assembled plasmonic nanojunctions

Chio, W.-I. K., Peveler, W. J. , Assaf, K. I., Moorthy, S., Nau, W. M., Parkin, I. P., Olivo, M. and Lee, T.-C. (2019) Selective detection of nitroexplosives using molecular recognition within self-assembled plasmonic nanojunctions. Journal of Physical Chemistry C, 123(25), pp. 15769-15776. (doi: 10.1021/acs.jpcc.9b02363) (PMID:31303905) (PMCID:PMC6614880)

Abstract

We demonstrate that the reproducibility of sensors for nitroaromatics based on surface-enhanced Raman spectroscopy (SERS) can be significantly improved via a hierarchical aqueous self-assembly approach mediated by the multifunctional macrocyclic molecule cucurbit[7]uril (CB[7]). Our approach is enabled by the novel host–guest complexation between CB[7] and an explosive marker 2,4-dinitrotoluene (DNT). Binding studies are performed using experimental and computation techniques to quantify key binding parameters for the first time. This supramolecular complexation allows DNT to be positioned in close proximity to the plasmonic hotspots within aggregates of CB[7] and gold nanoparticles, resulting in significant SERS signals with a detection limit of ∼1 μM. The supramolecular ensemble is selective against a structurally similar nitroaromatics owing to the molecular-recognition nature of the complexation as well as tolerant against the presence of model organic contaminants that bind strongly to the SERS substrates.

• Item Type: Articles
• Additional Information: SM and TCL are grateful to the Research Project Grant (RPG2016-393) funded by the Leverhulme Trust. WIKC, IPP, MO, and TCL are grateful to the Studentship funded by the A*STAR-UCL Research Attachment Programme through the EPSRC M3S CDT (EP/L015862/1). WJP acknowledges the University of Glasgow for a Lord Kelvin Adam Smith Fellowship. KIA and WMN thank the DFG for grant NA686/8 within the priority program SPP 1807 “Control of London Dispersion Interactions in Molecular Chemistry”.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Peveler, Dr William
• Authors: Chio, W.-I. K., Peveler, W. J., Assaf, K. I., Moorthy, S., Nau, W. M., Parkin, I. P., Olivo, M., and Lee, T.-C.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of Physical Chemistry C
• Publisher: American Chemical Society
• ISSN: 1932-7447
• ISSN (Online): 1932-7455
• Published Online: 23 April 2019
• Copyright Holders: Copyright © 2019 American Chemical Society
• First Published: First published in Journal of Physical Chemistry C 123(25): 15769-15776
• Publisher Policy: Reproduced under a Creative Commons License