Hydrothermally derived reduced and hierarchically porous biochar for rapid and sensitive electrochemical detection of benzo[a]pyrene

Benzo[a]pyrene (BaP), as a typical polycyclic aromatic hydrocarbon, is severely hazardous to human for having great carcinogenic and teratogenic activities. Here, we propose a cascade electrochemical reaction-based BaP detection method by using novel synthesized reduced and hierarchically porous biochar (RP-BC) as conductive and analysts binding material. The RP-BC was synthesized by green hydrothermal reduction of sugarcane derived biochar, which was demonstrated to have huge specific surface area with hierarchically porous structures, great content of sp2 carbon, and fast electron transfer ability. The RP-BC film coated on glassy carbon electrode could preferentially adsorb and enrich BaP by strong π-π electron donor-acceptor (EDA) interaction and pore interception effect, so fast (5 min) and selective detection of BaP was achieved. Moreover, the low detection limit was 0.090 nmol·mL−1 with linear range being 0.32 to 80 nmol·mL−1. In addition, the detection of BaP in groundwater and tap water was realized with satisfactory results, suggesting the potential of practical environmental monitoring.