A silica xerogel thin film based fluorescent sensor for pentachlorophenol rapid trace detection

We report a fluorescence approach to rapid detection of pentachlorophenol (PCP) by using 9-fluorenylmethanol (FMOC-OH) doped silica xerogel thin film (denoted as FMOC-OH@silica xerogel thin film). The FMOC-OH@silica xerogel thin film exhibits not only a very shorter discrimination time, but also with a high detection sensitivity to PCP with a lower limit down to 10 nM based on fluorescence quenching effect and a broad detection selectivity among diverse PCP analogues. The mechanism for fluorescence changes is mainly attributed to the fluorescence resonance energy transfer (FRET) between the analyte PCP and the fluorophore FMOC-OH in silica xerogel thin film, and the different sensitivities and selectivities to other PCP analogues are ascribed to different FRET efficiencies, pathways and fluorescence quantum yields. The FMOC-OH @silica xerogel thin film has potentials in detecting and monitoring trace PCP in the environment.