The Use of an Enzymatic SPR Biosensor for the Quantification of Congo Red in Water

The colorant Congo Red is a synthetic azo dye, whose metabolites, depending on the doses, can be harmful for the environment and human health. Congo red can pollute the water mainly by the release of wastewater from different industries. Different metho-dologies have been proposed for its quantification, many of them including the use of spectrophotometry and HPLC, but some processes can be tedious and require various steps of sample preparation. In this work, a biosensor with immobilized enzymes lac-cases and Surface Plasmon Resonance (SPR) was used, achieving a LOD of 0.008 mg L-1, a LOQ of 0.028 mg L-1, a R2 value of 0.9926 and a working range from 0-3.5 mg L-1. Furt-hermore, the method was teste don spiked samples of tap water, with a % of recovery of 104.48%±10.41. The LOD was lower than other reported techniques for the detection of Congo Red, suitable for its use in real samples of tap water, and with a simple prepara-tion process.