Fig. 1. (a) Illustration of the excitation of the LSPR of spherical nanoparticles; Theoretical simulations of the electromagnetic field enhancement around silver nanoparticles of (b) a triangular nanoparticle (700 nm), a dimer of spherical nanoparticles (520 nm), and an ellipsoidal nanoparticle (695 nm)^[12]

Fig. 2. The UV-Vis absorption spectrum (a) and scanning electron micrograph (SEM) (b) of as-prepared colloidal Au NPs^[13]

Fig. 3. Schematic representation of the TLC-SERS study of continuous raman scanning^[15]

Fig. 4. Schematic illustration of TLC-SERS for on-site detection of substituted aromatic pollutants in wastewater
Two insert images show the SEM characterization of the blank TLC plate and the silver nanoparticles deposited TLC plate, respectively^[33]

Fig. 5. Schematic illustration of the QuEChERS combined with TLC-SERS for detection of papaverine and nascapine^[35]

Fig. 6. Schematic illustration of TLC-SERS for detection of hydrophilic and hydrophobic adulterants in BDS^[36]

Fig. 7. SEM image of Au NPs used for SERS (a) and diatomite TLC plate (b), photo of silica gel (c) and diatomite (d) plate after TLC separation of iodine colorimetry, SERS spectra of PEA separated by silica gel plate (e) and diatomite plate (f) from plasma at different concentrations^[16]