Detection of Lead in River Water Samples Applying Cantilever Nanobiosensor

Contamination of water sources with lead has been a problem because it is a toxic heavy metal. Detection and monitoring are important for both the environment and human health. In this paper, we present an application of cantilever nanobiosensors that can detect contamination traces of lead (Pb) in real river water samples. The urease and alkaline phosphatase enzymes are used in the device as a biological element with high sensitivity in Pb detection. By change in deflection of the cantilever nanobiosensor in contact with the liquid solution (water), the response was the detection of trace amounts of Pb in water. When using ultrapure water (white), the nanobiosensors did not demonstrate voltage response. The detection limit was in femtograms per milliliter (parts per trillion) for phosphatase alkaline and urease nanobiosensors with good recovery results. The matrix effect was minimized with the dilution of river water in the ratio 1:1 with the working solution. The nanobiosensors demonstrated are efficient in the detection of the presence of Pb in real samples. Thus, the developed cantilever nanobiosensors showed suitability for heavy metal detection in water and could be a promising tool in the environmental area.