Bimetallic MOF-Based Enzyme-Free Sensor for Highly Sensitive and Selective Detection of Dopamine

A bimetallic metal organic frameworks termed as Fe2Ni MIL-88B was fabricated as an enzyme-free dopamine (DA) sensor, which was designed with crystalline porous structure and synthesized by a facile hydrothermal technique. To gain insight into the structure and morphology of Fe2Ni MIL-88B, a series of characterizations such as fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopic (TEM) and field emission scanning electron microscopic (FE-SEM) had been performed, proving the as-prepared composite owned hexagonal rod-like structure with the size 633 nm–967 nm in length and 100 nm–167 nm in width. The Fe2Ni MIL-88B modified glass carbon electrode (Fe2Ni MIL-88B/GCE) possessed an excellent electrochemical catalytic performance to DA which are derived from electrochemical test, having been reported to own wider linear range from 1.2 μM–1.8 mM, lower detection limit of 0.40 μM (S/N = 3) and higher sensitivity of 124.7 μA mM−1 cm−2. The proposed sensor exhibited acceptable stability, repeatability and achievability for analyzing real samples. All the evidence suggested a potential application of Fe2Ni MIL-88B in DA detection.