CANTILEVER NANOBIOSENSOR BASED ON THE ENZYME UREASE FOR DETECTION OF HEAVY METALS

Abstract Cantilever nanobiosensors have emerged as an alternative to conventional methods of analysis to monitor heavy metals, which are being highlighted by detecting substances at the micro and nanoscale through the use of sensor layers. In the present study, a new cantilever nanobiosensor was developed functionalized with urease enzyme by self-assembled monolayers for the detection of heavy metals (lead, nickel, cadmium, zinc, cobalt, and aluminum) in water. From the calibration curves, using the statistical method of Principal Component Analysis, it was possible to observe that the nanobiosensor was highly efficient in heavy metal discrimination. The nanobiosensor presented high sensitivity, good stability, and a detection limit in the ppb range during 30 days of storage. The surface characterization by scanning electron microscopy confirmed the cantilever functionalization and the sensing layer deposition. The cantilever nanobiosensor designs based on tensile surface stress measured by changes in voltage suggest the proposed mechanism of the adsorption of heavy metal by the urease enzyme. Thus, the cantilever nanobiosensor with urease enzyme was able to detect heavy metals in water and could be a promising tool for heavy metal detection.