Enhanced Sensitivity of 4‐Chlorophenol Detection by Use of Nitrobenzene as a Liquid Membrane over a Carbon Nanotube‐Modified Glassy Carbon Electrode

The analytical utility of nitrobenzene as a liquid membrane for the detection of hydrophobic compounds was examined with a glassy carbon electrode, using 4‐chlorophenol as the model analyte. Electrochemical experiments indicated a large partition coefficient for the entry of 4‐chlorophenol into the nitrobenzene (7.6×10²±1.5×10²). This was combined with an increase in effective electrode area by coating with single‐walled nanotubes. Differential pulse voltammetry produced a linear response across the range 0.3 nM to 1.5 nM with a sensitivity of 1.1×10^?5 A nM^?1 cm^?2. To the best of our knowledge, this limit of detection for phenol is lower than other nonenzymatic modifications of carbon.