title: Colorimetric detection of melamine in milk by citrate-stabilized gold nanoparticles.
abstract: Here, we report a simple and sensitive colorimetric method for detection of melamine in milk using gold nanoparticles (AuNPs). AuNPs of 21-nm size were synthesized by the citrate reduction method. The method is based on the principle that the melamine causes the aggregation of AuNPs and, hence, the wine red color of AuNPs changes to blue or purple. This change in color can be visualized with the naked eye or an ultraviolet-visible (UV-Vis) spectrometer. Under optimized conditions, AuNPs are highly specific for melamine and can detect melamine down to a concentration of 0.05 mg L(-1).
authors.affiliation: Dairy Chemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India. Electronic address: nkft87@gmail.com.
authors.forename: Naveen
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Dairy Chemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India.
authors.forename: Raman
authors.initials: R
authors.lastname: Seth
authors.affiliation: Dairy Chemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India.
authors.forename: Harish
authors.initials: H
authors.lastname: Kumar
mesh_terms: D000818:Animals; D002138:Calibration; D019343:Citric Acid / Q000737:chemistry*; D003116:Color; D003124:Colorimetry / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008892:Milk / Q000737:chemistry*; D014227:Triazines / Q000032:analysis*
chemical_list: D014227:Triazines; D019343:Citric Acid; D006046:Gold; C011907:melamine
keywords: Gold nanoparticles; Limit of detection; Melamine; Milk; Quantification