Colorimetric detection of neomycin sulfate in tilapia based on plasmonic core-shell Au@PVP nanoparticles.

The rapid colorimetric detection of neomycin sulfate has been achieved using polyvinyl pyrrolidone shell coated gold nanoparticle (Au@PVP NPs) sol. We also observed that, the aggregation of Au@PVP NPs, possibly caused by the hydrogen bonds formed between neomycin sulfate and PVP shell, generates a new surface plasmon resonance absorption in the wavelength of 600 ~ 700 nm. The proposed method showed an excellent performance towards the determination of neomycin sulfate in wide linear range from 0.01 ~ 10 µM with a correlation coefficient of 0.99 and low detection limit of 1 nM. After extracted with trichloroacetic acid and treated with hot chloroform, neomycin sulfate in the tilapia fish samples was detected with satisfied recovery. Additionally, the high selectivity of Au@PVP NPs sol towards neomycin sulfate has been achieved even in presence of common interfering agents. This method has the advantages of high sensitivity, rapidity, specificity, low cost and no complicated pretreatment procedure.