Fig. 4From: A Widely Applicable Silver Sol for TLC Detection with Rich and Stable SERS FeaturesLong stable period provided by the AgNPs-DMF sols. a TLC-SERS spectra of GLC on AgNPs-DMF as a function of laser irradiation time. A corresponding contour plot is shown under the SERS spectra. b Relationship between exposure time and relative intensity of the 789-cm−1 band and 865-cm−1 bandBack to article page