Conjugated Polyelectrolyte/Graphene Multilayer Films for Simultaneous Electrochemical Sensing of Three Monohydroxylated Polycyclic Aromatic Hydrocarbons

Monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) are polycyclic aromatic hydrocarbon (PAH) metabolites that have been used widely as biomarkers for evaluating human PAH exposure. In this paper, we present the design and synthesis of a water-soluble conjugated polyelectrolyte (PBCSO 3 Na) for use in a PBCSO 3 Na/graphene multilayer electrochemical sensor prepared using a layer-by-layer self-assembly method for the simultaneous detection of three OH-PAHs (namely, 2-hydroxynaphthalene, 3-hydroxyphenanthrene, and 1-hydroxypyrene). The homogeneous and controllable PBCSO 3 Na and graphene multilayer films formed via π–π interactions not only disperse well in water owing to the ionic side chains of PBCSO 3 Na but also prevent the aggregation of graphene by electrostatic repulsion. The developed sensor exhibits high electrocatalytic activities for the target OH-PAHs, and the electrochemical responses obtained under the optimal experimental parameters for the detection of 2-hydroxynaphthalene, 3-hydroxyphenanthrene, and 1-hydroxypyrene are found to be linear in the concentration ranges of 10–140, 10–160, and 20–130 nM with detection limits of 1.43, 2.31, and 10.42 nM for a signal-to-noise ratio of 3, respectively. The practical analytical applicability of the proposed sensor is verified by its application to spiked human urine samples, and the results demonstrate appropriate anti-interference capabilities and excellent recoveries in the range of 99.0–106.0%.