SPR-based assay kit for rapid determination of Pb.

A recyclable optical nanosensor was developed by immobilizing l-tyrosine functionalized silver nanoparticles (AgNPs) on the polyethylene terephthalate (PET) substrate for rapid determination of Pb ions. At first, the l-tyrosine functionalized AgNPs were assessed in the solution phase; the response time was lower than 15 s, and a limit of detection lower than 9 nM was obtained in the dynamic range of 1-1000 nM. For fabrication of the optical assay kit, the design of experiment (DOE) was used to optimize the immobilization efficiency of the nanoparticles on PET films by studying AgNO concentration and pH as two crucial parameters.