A highly sensitive immunochromatographic assay for lead ions in drinking water based on antibody-oriented probe and silver enhancement

Lead ions are a toxic metal that can enter the human body through the diet and negatively impact human health. A wide variety of foods, such as vegetables, meat, aquatic product, and drinking water, can be contaminated with lead ions. In this study, a highly sensitive immunochromatographic assay (ICA) based on antibody-oriented probe and silver enhancement was established for the qualitative and quantitative determination of lead ions in drinking water. The recombinant protein A (PrA) was used in probe preparation to improve antibody bioactivity while silver enhancement method was applied to enhance the signal reporter of ICA. It was determined that the visual limit of detection and the scanning limit of quantification of the ICA based on antibody-oriented probe and silver enhancement for lead ions in drinking water were 0.2 ng/mL and 0.08 ng/mL, respectively. The results obtained from developed ICA strip and ICP-MS had no obvious difference using statistical analysis of t test. Compared to previously reported ICA methods for lead ions, the developed ICA method enabled analyzing lead ions in drinking water with a superior sensitivity and detection range.