A colorimetric approach towards polycyclic aromatic hydrocarbon sensing

The colorimetric detection of polycyclic aromatic hydrocarbons (PAHs) was achieved using photochromic compounds. This technique exploits the ability of the photochromic compound to reversibly change from a colourless to a coloured compound using ultraviolet light and visible light. In the presence of a PAH, this photoisomerization is inhibited. The degree of inhibition corresponded to the molar absorptivity and excitation wavelength of the PAH, and with a limit of detection in the micromolar range, the current method delivers a highly sensitive and selective technology. In addition, PAH mixtures were successfully identified using this method, providing a potentially fast in-field sensing technology for the identification of likely sources of spilled oil