Development of detection system for lead ions in mixture solutions using UV-Vis measurements with peptide immobilized microbeads.

Environmental pollution caused by heavy metals are problems worldwide. In particular, pollution and poisoning by lead ions (Pb) continue to be common and serious problems. Hence, there is a need for a widely usable method to easily detect Pb from solutions containing organic materials from environmental water such as seas, ponds, etc. Here, we established a system to easily detect Pb from such mixture solutions using Pb binding peptide immobilized beads (peptidyl beads) and ultraviolet (UV) absorption measurements. This method could detect Pb at low concentrations equivalent to inductively coupled plasmon-atomic emission spectroscopy (ICP-AES). Using the detected values to create a calibration curve, it was found that there was a positive correlation between the concentration of Pb and absorbance, which also made it possible to quantify sub-µM Pb in the solutions. Furthermore, Pb was detected and quantified under mixed conditions of environmental water such as seas, rivers, and ponds. This method is expected to become a versatile and easy-to-use Pb detection method for end-users worldwide.