Surface enhanced Raman spectroscopyNanoparticlesPlant hormones detectionMicrofluidic systemRaman active substrateTANDEM MASS-SPECTROMETRYCHEMICAL ENHANCEMENTLIGAND-EXCHANGEPLASMONIC NANOSTRUCTURESULTRASENSITIVE DETECTIONMAGNETIC NANOPARTICLESELECTROMAGNETIC THEORYSILVER NANOPARTICLESFLUORESCENT-PROBESGOLD NANOPARTICLES