One-step detection of multi-pollutants with different sizes in water by using cellulose-based composites

The contamination of multi-pollutants in source water, e.g., bacterial and organic pollutants, has been a long-term problem that influences our daily lives and industries. Despite great efforts in developing rapid detection methods, most of them require extra operations for pollutant separation and/or analyte purification prior to detection, which are very complicated and can easily cause secondary pollution. Here we report a one-step and effective detection method for multi-pollutants in water, by fabricating a cellulose-based platform through the in-situ growth of gold nanoparticles. Our experiments show that it allows the self-separation of bacterial and organic pollutants or multi-molecules in different sizes, e.g., human serum albumin/phenol mixtures and carbaryl/dimercaptosuccinic acid mixtures, and meanwhile, has the effective surface-enhanced Raman scattering (SERS) activity for separated pollutants/molecules. We further demonstrate that the SERS activity has a positive relation with the analyte concentration and ensures a very low limit of detection (down to 10 −12  M). We note that this detection platform excludes extra operations for pollutant separation and analyte purification, and thus promises a wide range of application fields, e.g., water research, food sanitation, and environmental engineering.