Polydopamine-coated magnetic Spirulina nanocomposite for efficient magnetic dispersive solid-phase extraction of aflatoxins in pistachio

•Polydopamine-coated magnetic Spirulina nanocomposite was successfully synthesized.•Nanocomposite was used for efficient adsorption of aflatoxins in pistachio.•Easy adsorbent separation from the sample matrix was achieved by a magnetic field.•Adsorption process including hydrogen bonding, hydrophobic and π-π interactions.•Comparative evaluations showed good figures of merit by the developed method.