Two dimensional FeVO₄ nanoflakes decorated on Ti₃C₂ MXene hybrid nanocomposites as a novel effective electrochemical biosensor for ultrasensitive and selective detection of serotonin (5-HT)

Serotonin (5-HT) is a neurotransmitter involved in various pathological and physiological processes. The development of novel electrochemical sensor is of significant interest for effective measurement of 5-HT in pharmaceutical and disease diagnosis applications. In this work, two-dimensional iron vanadate nanoflakes (FeVO₄ NFs) supported on Ti₃C₂ MXene hybrid nanocomposites was fabricated for the ultrasensitive and highly selective electrochemical detection of (5-HT). The morphology and crystalline phase of the as-synthesized nanocomposites was analyzed by various characterization techniques. The morphological studies of the hybrid nanocomposites reveals that FeVO₄ NFs are uniformly decorated on the Ti₃C₂ MXene surface. Differential pulse voltammetry (DPV) and cyclic voltammetry (CV) characterization of FeVO₄@Ti₃C₂ MXene on screen printed carbon electrode (SPCE) exhibits enhanced electrochemical activity towards 5-HT oxidation. Under optimized conditions, FeVO₄@Ti₃C₂ MXene (SPCE) reveals a linear concentration of 25 to 750 nM, with a detection limit of 5.88 nM towards the determination of (5-HT) and the calculated sensitivity of 3.0 μA μM⁻¹ cm⁻². In addition, the fabricated electrochemical biosensor delivers excellent stability, selectivity and reproducibility with the existence of interfering active compounds enabling the detection of 5-HT. Furthermore, the FeVO₄@ Ti₃C₂ MXene (SPCE) biosensor displays satisfactory results in real sample analysis such as human serum.