Measurement of lead in seawater using gold nanoparticles modified screen printed carbon electrode

Due to their low detection limits, various types of spectrometry techniques have been used for determining lead [Pb(II)] in water. However, these methods are not applicable for the on-site measurements of Pb(II) since the equipment is too bulky and skilled laboratory staff are needed. In this study, coastal water samples were collected from different sites close to two coastal industrial complexes in Korea. Their Pb(II) concentrations were determined using electrodeposited gold nanoparticles (AuNPs) on a disposable screen-printed carbon electrode. Square wave anodic stripping voltammetry was used to enhance the sensitivity of the Pb(II) detection level with less than 5 μg/L. The square wave anodic stripping voltammetric response for high sensitivity was 0.018 μA/μg/L, the Pb(II) concentration range was 2 to 500 μg/L at the deposition time of 180 s, and the detection limit was 4.4 μg/L with good selectivity. These results indicate that there was no significant difference between our sensor and the conventional spectrometry method in precision and accuracy. The AuNPs based sensor demonstrated long-Term stability for up to 7 days while being used in the continuous monitoring of 100 μg/L Pb(II) in seawater. An RSD value of 2.7% was obtained, and the sensor retained 93% of its initial activity after 7 days.