Highly fluorescent graphene oxide as a facile and novel sensor for the determination of hypochlorous acid

• Fluorescent graphene oxide was obtained through the modification of hexylenediamine.
• This fluorescent nanomaterial is directly applied to detect HOCl with a LOD of 3.5 μM.
• The fluorescence quenching by HOCl may be due to an intramolecular charge-transfer.
• The good recovery test suggests the method is available for the detection HOCl in tap water.

The highly fluorescent graphene oxide modified by hexylenediamine was fabricated to determinate the amount of hypochlorous acid (HOCl) in aqueous solution. The fluorescence of graphene oxide was quenched by HOCl based on the intramolecular charge-transfer (ICT) between grapheme oxide and chloramines, which formed through the oxidation of amino groups at the lateral edge of graphene oxide by HOCl. This method shows low interference and high selectivity for HOCl with a limit of detection of 3.5 μM in water. Additionally, the fluorescence graphene oxide with a quantum yield of 11.2% showed a good spike and recovery test for detection of HOCl in tap water, suggesting that the fluorescent probe is a potential strategy for the accurate determination of HOCl in realistic condition.