Colorimetric-Based Detection of TNT Explosives Using Functionalized Silica Nanoparticles

Sensors

Noorhayati Idros²  Man Yi Ho²  Mike Pivnenko²  Malik M. Qasim²  Hua Xu¹  Zhongze Gu¹  Daping Chu² 

[1] State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Sipailou 2, Nanjing 210096, China; E-Mails:;Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, UK; E-Mails:

关键词: explosives;    functionalized nanoparticles;    colorimetric;    label-free;    self-assembly film;    aptamer;   

DOI  :  10.3390/s150612891

来源: mdpi

【 摘 要 】

This proof-of-concept study proposes a novel sensing mechanism for selective and label-free detection of 2,4,6-trinitrotoluene (TNT). It is realized by surface chemistry functionalization of silica nanoparticles (NPs) with 3-aminopropyl-triethoxysilane (APTES). The primary amine anchored to the surface of the silica nanoparticles (SiO₂-NH₂) acts as a capturing probe for TNT target binding to form Meisenheimer amine–TNT complexes. A colorimetric change of the self-assembled (SAM) NP samples from the initial green of a SiO₂-NH₂ nanoparticle film towards red was observed after successful attachment of TNT, which was confirmed as a result of the increased separation between the nanoparticles. The shift in the peak wavelength of the reflected light normal to the film surface (λ_peak) and the associated change of the peak width were measured, and a merit function taking into account their combined effect was proposed for the detection of TNT concentrations from 10⁻¹² to 10⁻⁴ molar. The selectivity of our sensing approach is confirmed by using TNT-bound nanoparticles incubated in AptamerX, with 2,4-dinitrotoluene (DNT) and toluene used as control and baseline, respectively. Our results show the repeatable systematic color change with the TNT concentration and the possibility to develop a robust, easy-to-use, and low-cost TNT detection method for performing a sensitive, reliable, and semi-quantitative detection in a wide detection range.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.