Visual Recognition and Detection of Clindamycin by Au@Ag Core–Shell Nanoparticles

[Image: see text] The work described a new colorimetric sensor for the quantitative detection of clindamycin based on Au@Ag core–shell nanoparticles (Au@Ag NPs). The obtained Au@Ag NPs were characterized by transmission electron microscopy (TEM) and ultraviolet and visible spectrophotometry (UV–vis). When Au@Ag NPs were added to a clindamycin solution, it can be observed that the color immediately changed from bright yellow to gray-blue and the absorption spectrum also changed, realizing the visual detection of clindamycin. Under optimal conditions, the absorption ratio (A(546)/A(400)) of the UV–vis spectra increased linearly with the concentration of clindamycin ranging from 6.25 × 10(–7) to 7.50 × 10(–6) mol/L (R(2) = 0.9945), with a limit of detection (LOD) of 2.00 × 10(–7) mol/L and good recovery of 100.0–102.0% (relative standard deviation (RSD) < 2%). The detection process was convenient without complicated instruments. Compared with other analytes, the Au@Ag NPs detection system has good selectivity for clindamycin. In addition, the Au@Ag NPs colorimetric sensor was successfully used to determine clindamycin in human urine samples. This study provides a simple, rapid, intuitive, and low-cost visualization analysis method of clindamycin, which was helpful for the visualization detection of other targets.