In situ growth of covalent organic frameworks TpBD on electrode for electrochemical determination of aflatoxin M1

An in situ growth strategy for construction of covalent organic frameworks (COFs) TpBD on glassy carbon electrode using p-aminobenzoic acid and ethylenediamine as connector is introduced. The fabricated electrode was used for electrochemical biosensing of aflatoxin M1 in milk samples combined with magnetic nanoparticles, which acted as probe carriers. The developed electrochemical biosensor exhibited high selectivity and sensitivity toward aflatoxin M1 with a detection limit of 0.15 ng/mL (S/N = 3). Moreover, the covalent bonding of TpBD on the glassy carbon electrode has good stability, which retained 76% of the initial signal after 15 days storage at room temperature. This work provides a valuable case for in situ growth of COFs TpBD on the electrode, and the proposed synthetic route is expected to provide a powerful tool for the wide application of other functional COFs in electrochemical biosensor.