A new ratiometric electrochemical sensor for sensitive detection of bisphenol A based on poly-β-cyclodextrin/electroreduced graphene modified glassy carbon electrode

• A ratiometric electrochemical assay for bisphenol A.
• A poly-β-CD/electroreduced graphene modified glassy carbon electrode was developed.
• The proposed ratiometric electrochemical sensor shows good analytical performance.

A ratiometric electrochemical sensor has been developed for highly sensitive and selective detection of bisphenol A. The assay strategy was based on the competitive host–guest interaction between poly-β-cyclodextrin/electroreduced graphene (Pβ-CD/EG) and Rhodamine B (RhB) probe or bisphenol A (BPA) target molecules. RhB can enter into the hydrophobic inner cavity of β-CD and shows an obvious oxidation peak on the Pβ-CD/EG modified glassy carbon electrode. In the presence of BPA, the RhB molecules are displaced by BPA because the host–guest interaction between β-CD and BPA is stronger than that between β-CD and RhB. As a result, the oxidation peak current of RhB (IRhB) decreases and the oxidation peak current of BPA (IBPA) increases correspondingly. The logarithmic value of IBPA/IRhB is linear with the logarithm of BPA concentration in the range of 1–6000 nM and the detection limit is 52 pM (S/N = 3). This strategy provides a new approach for sensitive detection of BPA, and has promising applications in the detection of organic pollutants in real environmental samples.

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