A blood compatible, high-efficient sensor for detection of Cr(VI) in whole blood

•A sensor with PANI/Hep/MTA/MGCE for detection of Cr(VI) in whole blood was obtained.•The sensor exhibited outstanding electrochemical performance for Cr(VI) detection.•The sensor can detect Cr(VI) in whole blood due to its antibiofouling property. Fast and accurate test Cr(VI) in the whole blood is particularly critical for the treatment and prevention of Cr(VI) poisoning. Here, a blood compatible, high-efficient sensor based on the magnetic glassy carbon electrode (MGCE) that modified by conductive polyaniline (PANI), heparin and tannin modified Fe3O4 nanoparticles (magnetic tannin-modified adsorbent, MTA) with high adsorption ability toward Cr(VI) ions was developed. Results indicated the designed PANI/Hep/MTA/MGCE exhibited high sensitivity for Cr(VI) in the concentration range of 10−7 to 10−4 ppm with a 0.87 μM detection limit (3σ method). In particular, this prepared sensor not only exhibited outstanding electrochemical performance for Cr(VI) detection, but also possessed good antibiofouling characteristics due to the existence of heparin, which can provide guarantee for direct detection of Cr(VI) in the whole blood.