The point-of-care colorimetric detection of the biomarker of phenylamine in the human urine based on Tb3+ functionalized metal-organic framework

Abstract

Phenylamine has been recognized as one of the most important industrially relevant ingredient and a crucial intermediate in chemical products. Yet, its internal exposure detection in human remains largely elusive due to the lack of potent monitoring method. Hereby this issue is addressed with a probe based on lanthanide functionalized organic-inorganic hybrid material Al(OH)(bpydc) (1) through post-synthetically modified metal-organic framework. The as-synthesized Tb³⁺@1 exhibits the strong luminescence of Tb³⁺ originated from efficient energy transfer from the ligand, which can sense the biological metabolite p-aminophenol (PAP) of the phenylamine in the human urine. Linear correlation between the integrated fluorescence intensity and the concentration of PAP was investigated, enabling quantitative analysis of PAP in physiologically ranges (0.005-5 mg mL^-1) with low detection limit (5 μg mL^-1). This probe demonstrates excellent sensitivity, high selectivity, good reusability and quick response to PAP. Furthermore, a simple and rapid smartphone-based medical portable test paper was developed, whose quantitative color change can be easily distinguished visually. Hence, the PAP sensing platform can serve as a potential diagnostic tool for home monitoring of PAP.

Keywords: Biomarker of phenylamine in the human urine; Chemical sensing; Colorimetric detection; Luminescence; Terbium ion functionalized metal-organic framework.