A disposable rhodium nanoparticle-modified screen-printed sensor for direct determination of bromide anions

The demand for bromide determination has increased over recent years. Sources of bromide contamination can be found in brines from hydraulic fracturing, pesticides and brominated polymers. Widely used in different applications, the bromide anion is present in the composition of several compounds. In this paper, we present a new selective voltammetric method for bromide determination, based on a screen-printed carbon electrode (SPCE) modified with rhodium nanoparticles (Rh-Nps), that is used as a sensing platform. The modification of the electrode surface with Rh-Nps and the presence of chloride in the sample, improved device performance, increasing the sensitivity of the Rh/SPCE-based sensor for bromide determination. The proposed sensor is simple to manufacture, easy to operate, and it offers a fast and accurate analysis. A single drop of the sample on the sensor is sufficient for the determination of bromide through measurement of voltammetric cathodic peaks, generated after a previous anodic stripping step. This disposable sensor offers a detection limit of 39 mu M, with a calibration range up to 40 mM, and a sensitivity of 23.28 mu A/mM. Its application to real-life samples evidenced recovery values close to 100%, demonstrating the powerful analytical performance of the proposed method.