A new SERS substrate based on silver nanoparticle functionalized polymethacrylate monoliths in a capillary, and it application to the trace determination of pesticides

We have developed a simple, sensitive and practical substrate for surface enhanced Raman scattering (SERS). It consists of a column material that is obtained by modifying the surface of (glycidyl methacrylate)-co-(ethylene dimethacrylate) capillary monoliths with silver nanoparticles. This new SERS column substrate was applied to the determination of 4-mercaptopyridine (4-Mpy) and Rhodamine 6G (R6G) to give detection limits as low as 100 and 10 pM, respectively. The calculated enhancement factor is approximately 1.2 x 10(8). This represents a substantial improvement over conventional colloidal substrates. The new substrate was applied to the determination of residues of the pesticide phosmet and gave a detection limit of 3 mu ga (TM) L-1, with a linear response in the 3 to 1000 mu ga (TM) L-1 concentration range (R-2 = 0.995). Additionally, 0.2 mga (TM) kg(-1) of phosmet on apples and oranges, and of 0.5 mga (TM) kg(-1) on tea leaves were detectable via SERS using this column along with a simple extraction process. The above LODs are well below the tolerance level prescribed by National Standard of China. Thus, this simple method is highly efficient, sensitive, and affordable and introduces a SERS-based trace detection suitable for real-world applications, especially for the determination of pesticides.