Electropositive far-ultraviolet carbon nanoparticles-based photoluminescent photoinduced-electron transfer sensor for sodium dodecyl sulfate and sodium lauryl sulfonate detection

Unrestrained use of sodium dodecyl sulfate (SDS) and sodium lauryl sulfonate (SLS) in industry, agriculture and household are causing its subsequent accumulation in waterways, which can cause the adverse effect on various living organisms, especially aquatic organisms. Therefore, an efficient and rapid technique to detect SDS and SLS in the environment is urgently demanded. Herein, a novel far-ultraviolet emission carbon nanoparticles (FCNPs, quantum yield of ∼15.47%) with positive charges was synthesized by one-pot simple hydrothermal route using 5-hydroxytryptamine as the precursor, and applied to the detection of SDS and SLS. When the exposure to SDS and SLS, the FCNPs displayed anionic detergent-sensitive fluorescent quenching. The mechanism was proved to be that enrichment-positive charge of –NH₃⁺ groups can strongly combine with negatively charged SDS/SLS molecules through electrostatic adsorption, resulting in luminescent quenching of FCNPs via photoinduced-electron transfer mechanism. By using this sensing platform, there are two good linear relationships between the quenching degree of the FCNPs and the concentrations of SDS and SLS in the range of 5.0 nM–50 μM and 2.5 nM to 50 μM with almost the same LOD of ∼2.5 nM, respectively. Moreover, this sensing platform has been successfully applied to detect the SDS and SLS in real domestic wastewater samples. Therefore, the electropositive luminescent FCNPs might possess enormously potential utilization in the detection of anionic detergent for environmental protection.