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Application of thermoresponsive hydrogel/gold nanorods composites in the detection of diquat
Caiyun Jiang1, Xiaoyuan Ma2, Maoyun Xue3
1State Key Laboratory of Analytical Chemistry for Life Science, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China; Jiangsu Engineering and Research Center of Food Safety, Department of Engineering and Technology, Jiangsu Vocational Institute of Commerce, Nanjing 210007, China.
Abstract:
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.
