Au nanoparticles (AuNPs), amplifying surface plasmon resonance (SPR) signal, can be used in direct detection assays. In our study, AuNPs with different sizes (with the diameter of 17.26 nm, 24.13 nm and 30.35 nm, respectively) have been applied to enhance the SPR signal for detection of atrazine. The best sensitivity was obtained for AuNPs with diameter of 30.35 nm, and the minimum detectable concentration of atrazine was 1.0 ng/mL. The linear working range was from 1.0 ng/mL to 15.6 ng/mL. Spiked tests using atrazine revealed that recoveries were in the range 87.2-94.2% with good relative sta...
