In-situ colorimetric recognition of arylamine based on chemodosimeter-functionalized gold nanoparticle

Aniline, a typical example of arylamines, is one of most important raw materials in many industries. However, arylamine-related pollution in waters threatens the public health and environment along with their wide applications. In this work, a simple, fast, and convenient colorimetric sensing system was presented for the arylamine (e.g. aniline) recognition in aqueous media. The system was presented using diazonium salt (DS) decorated gold nanoparticles (AuNPs), based on the classic coupling reaction of arylamine with diazonium salt. DS-AuNPs showed an excellent response and a good sensitivity to aniline, and the limit of detection reached 0.5   μM for aniline in this work. There was a good linear relationship (R2   =   0.997) between the values of A640   nm/520   nm and aniline concentrations over a range of 5–60   μM, which covered the Chinese standard of the maximum permissible pollutant emission concentration for aniline. The introduction of arylamine (e.g. aniline) caused a rapid and obvious red-to-blue color change, so the arylamine-polluted water could be qualitatively recognized by our naked-eyes and quantitatively measured by absorbance changes.