Surface plasmon resonance based competitive immunoassay for Cd2+

In this study, a label-free, specific and sensitive surface plasmon resonance (SPR) based competitive immunoassay was used for detecting Cd2+ in water samples. The standard curve of the method for Cd2+ was constructed in the concentration range of 0–1000 ng mL−1. The values of IC50 and the LOD of the assay were found to be 23.58 and 1.25 ng mL−1. No cross-reactivity was found with other metal ions except Hg2+. The proposed method provides an alternative method for sensitive, specific and real-time determination of Cd2+ in real aqueous samples.