Surface-enhanced Raman scattering based determination on sulfamethazine using molecularly imprinted polymers...

Molecularly imprinted polymers (MIPs) were combined with surface-enhanced Raman scattering (SERS) and AgNPs were prepared by in situ reduction within the MIP for selective and sensitive detection of sulfamethazine (SMZ). The MIP@AgNPs composites were characterized in detail by several analytical techniques, showing the generation of polymers and the formation of AgNPs hot spots. The specific affinity and rapid adsorption equilibrium rates of MIP@AgNPs composites were verified by static and kinetic adsorption studies. The MIP@AgNPs with high selectivity and excellent sensitivity were used as SERS substrates to detect SMZ. A good linear correlation (R² = 0.996) in rang of 10^-10-10^-6 mol L^-1 was observed between the Raman signal (1596 cm^-1) and the concentration of SMZ. The limit of detection (LOD) was as low as 8.10 × 10^-11 mol L^-1 with relative standard deviations (RSD) of 6.32%. The good stability and reproducibility are also fully reflected in the SERS detection based on MIP@AgNPs. The method was successfully applied to the analysis of lake water samples, with recoveries in the range 85.1% to 102.5%. In summary, SERS detection based on MIP@AgNPs can be developed for a wider and broader range of practical applications. Schematic illustration of MIP@AgNPs sensor for the SERS detection of sulfamethazine.