Highly fluorescent polymeric nanoparticles based on melamine for facile detection of TNT in soil

Abstract

Analyte oriented selection of the preparation procedure is essential for improving the sensing performance. Herein, we report a one-step approach to synthesize highly fluorescent polymeric nanoparticles through a solvothermal method and their application for sensitive detection of TNT in soil samples by a fluorescence spectrometric method. The polymeric nanoparticles with bright cyan fluorescence were obtained through polycondensation between melamine and terephthalaldehyde at 180 °C for 3 h. The nanoparticles were fully characterized and the effect of synthesis methods was compared based on the fluorescence intensity and quantum yield (QY). The results indicated that trace amounts of TNT could effectively quench the fluorescence of the polymeric nanoparticles. The effect of the possible co-existing substances was systematically investigated and it was proved that nanoparticles could be used for selective and robust detection of TNT. A limit of detection of 1.8 nmol L⁻¹ was achieved. The standard addition recoveries for different soil samples were in the range of 95.3% and 106.4% with relative standard deviations below 5.2%.