Resonance light scattering method for detecting kanamycin in milk with enhanced sensitivity

In this paper, a resonance light scattering (RLS) method was developed for detecting kanamycin with high sensitivity and selectivity. Here, aptamer specific to kanamycin was utilized for recognizing and competitively binding with kanamycin, and gold nanoparticles (GNPs) were used as probes. After adding kanamycin into solutions containing aptamer and GNPs, the GNPs would aggregate in the presence of NaCl, which resulted in the RLS signal intensities enhanced dramatically. Based on this phenomenon, kanamycin can be detected in the range of 10 to 600 nM with a limit of detection as 1 nM, which is more sensitive than many other instrumental methods, especially the commonly used UV-visible spectroscopic method. Furthermore, we demonstrated that this method can be used for detecting kanamycin in milk samples with satisfactory results, which is meaningful for solving food safety problems.