Electrochemical sensor based on magnetic nanohybrids of multiple phthalocyanine doped ferrites/CMWCNTs for detection of rosmarinic acid.

Ferrites have attracted considerable attention in biosensor developments owing to their favorable electrochemical and magnetic properties. Speedy and trace analysis can be succeeded by the sensors based on magnetic nanohybrids. In this work, we reported a novel method for one-step synthesis of magnetic ferrites composed of Fe and phthalocyanine. After hybridization with carbonylated multi wall carbon nanotubes, a sensor based on Fe3O4-Pc-CMWCNTs nanocomposites was fabricated for the detection of rosmarinic acid (RA), a bioactive phytochemical. The sensor can be constructed within 30s without any complicated process. A comparison of electrochemical activity between ZnFe2O4-Pc-CMWCNTs and Fe3O4-Pc-CMWCNTs nanohybrids also has been accomplished in this work. Compared with ZnFe2O4-Pc-CMWCNTs based on commonly used ferrites, Fe3O4-Pc-CMWCNTs/MGCE exhibited a higher catalytical ability for the detection of RA. The sensor modified with Fe3O4-Pc-CMWCNTs displayed a low LOD of 0.182 μM with a wide linear range from 0.2 to 400 μM, which was 30 times more sensitive than the one based on ZnFe2O4-Pc-CMWCNTs. The obtained sensor also owned an excellent selectivity, reproducibility, repeatability, and stability, which made it achieve the measurements in plant sample and human serum.