Sensitive determination of benzo(a)pyrene in vegetable oils based on the electrochemiluminescence quenching of ruthenium (II) dipyrido[3,2-a:2′,3′-c]phenazine complex

•Benzo(a)pyrene (BaP) was detected via the ECL quenching of Ru-dppz.•The quenching was introduced by the π-π stacking between Ru-dppz and BaP.•The preferred interaction between Ru-dppz and BaP was calculated.•The linear range of BaP was 50 nM-15 μM and the LOD was estimated as 2.45 nM.•The recoveries confirmed the reliability for the detection of BaP in vegetable oils.