Selective nano-sensing approach for the determination of inorganic phosphate in human urine samples

A novel sensing approach is presented for the analysis of phosphate ions in human urine samples. The new sensor is based on the fluorescence energy transfer between a luminescent probe ([Tb-EDTA]^-1) and gold nanoparticles capped with a cetyltrimethylammonium bromide (Au NPs-CTAB). The strong affinity between CTAB receptors and phosphate ions results in a highly selective assay with minimum sample preparation steps. Possible chemical interference is monitored on real-time basis via luminescence lifetime analysis. The simplicity of analysis and the competitive limit of detection in the micro-molar concentration range provide a well-suited approach for routine monitoring of phosphate ions in numerous urine samples.