Massive immuno multiresidue screening of water pollutants

An immuno multiresidue screening assay in microarray format for the determination of complex chemical mixtures at the microgram per liter level, using antibody-functionalized gold nanoparticles, is presented. The analytical method relies on the use of a cocktail of nanogold-labeled specific antibodies, acting as recognition and detection species. The concept of multireside screening is proved by developing a multiplex assay on a compact disk support for the determination of 2-(2,4,5-trichlorophenoxy)propionic acid, 3-phenoxybenozic acid, 4-nitrophenol, alachlor, atrazine, azoxystrobin, chlorpyrifos, diazinon, diuron, endosulfan, fenthion, forchlorfenuron, imidacloprid, malathion, pentachlorophenol, pyraclostrobin, sulfasalazine, and triclosan, achieving detection limits of 0.07, 0.24, 10.9, 0.21, 0.14, 0.11, 0.11, 102, 0.36, 1.8, 1.7, 0.06, 0.08, 5.8, 1.0, 0.39, 0.003, and 12 μg/L, respectively. Due to the selectivity of the antibody-functionalized nanoparticles, the developed screening methodology allows the simultaneous determination of mixtures of water pollutants in a 10-plex configuration. The analytical performances were compared with those of reference chromatographic methods by the analysis of spiked water samples, the sensitivity and recovery results being in good agreement. The presented screening approach directly quantifies the concentration of complex chemical mixtures without sample treatment or preconcentration steps in a total time of 35 min.