Fabrication of Highly Sensitive Electrochemical Sensor Based on Chromium-Doped Ferrite Nanoparticles: Hybrid Graphene Nanosheets for the First Voltammetric Determination of Asenapine Maleate in Formulations and Human Plasma

Ferrite nanoparticles are interesting materials given their unique physical and chemical properties and wide applications. A novel electrochemical sensor based on a series of chromium-nano-ferrites {Fe 3+ [Fe 2+ Fe 3+ (1- x ) Cr 3+ x ]O 4 ; x (0.0–1.0} was fabricated for determination of Asenapine maleate (ASE.M). X-ray diffraction revealed the formation of crystallite nano-particles of lattice constant of (8.299–8.345 Å) with a single phase of cubic inverse spinel structures. Particle size and specific surface area were (9.10–27.60 nm) and (60–175 m 2 g −1 ) using Transmission electron microscopy and Brunnauer-Emmett-Teller (BET) analysis, respectively. Among this Cr x Fe (3− x ) O 4 series, (CrFe 2 O 4 ; x = 1) was appeared to get the smallest particles size and highest BET surface area. The charge transfer resistance (R CT ) of (2220, 1680, 765, and 490 Ω) were achieved for Cr x Fe (3− x ) O 4 NPs/CPE ( x = 0.0, 0.4, 0.8, and 1.0), respectively. CrFe 2 O 4 performance was then improved via incorporation of 2D-graphene atomic crystals in a new ferrite-graphene nanocomposite of [0.25%(w/w) CrFe 2 O 4 NPs: 7%(w/w) graphene nanosheets]. The feasibility of this sensor is achieved for determination of ASE.M in brand Saphris ® and local Asenapine pharmaceutical products. In addition, a wide linear concentration range of (6.5 × 10 −9 –1.0 × 10 −6 M) with LOD value of 8.88 × 10 −10 M were achieved in human plasma.