Application of thermoresponsive hydrogel/gold nanorods composites in the detection of diquat

Publication date: 1 November 2017
Source:Talanta, Volume 174
Author(s): Caiyun Jiang, Xiaoyuan Ma, Maoyun Xue, Hong-zhen Lian
Gallic acid (GA) was employed as a reducing agent for facile in situ preparation of gold nanorods (GNRs) in thermoresponsive P(NIPAM-NVP) hydrogel films. Based on the surface-enhanced Raman scattering (SERS) effect of GNRs and the enrichment effect of thermoresponsive hydrogel film on test molecules through a shrinkage process, the obtained P(NIPAM-NVP)/GNRs composites have been used as SERS substrate for the rapid detection of diquat. The influences of substrate pre-treatment, laser wavelength, and sample treatment method on diquat determination have been investigated comprehensively. The results showed the composite material to be a good SERS substrate for highly sensitive detection and a promising preconcentration matrix of diquat. The limit of detection of the proposed protocol was estimated to be 2.7×10⁻¹³molL⁻¹ for diquat. Notably, diquat could be concentrated with the enrichment factor of about 4 after three times swelling-shrinking processes of the hydrogel film.

Graphical abstract

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