Electrochemical Sensing of Serotonin by a Modified MnO2-Graphene Electrode

Abstract

The development of MnO2-graphene (MnO2-GR) composite by microwave irradiation method and its application as an electrode material for the selective determination of serotonin (SE), popularly known as “happy chemical”, is reported. Anchoring MnO2 nanoparticles on graphene, yielded MnO2-GR composite with a large surface area, improved electron transport, high conductivity and numerous channels for rapid diffusion of electrolyte ions. The composite was characterized by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning electron microscopy (SEM) for assessing the actual composition, structure and morphology. The MnO2-GR composite modified glassy carbon electrode (GCE) exhibited an excellent electrochemical activity towards the detection of SE in phosphate buffer saline (PBS) at physiological pH of 7.0. Under optimum conditions, the modified electrode could be applied to the quantification of serotonin by square wave voltammetry over a wide linear range of 0.1 to 800 µM with the lowest detection limit of 10 nM (S/N = 3). The newly fabricated sensor also exhibited attractive features such as good anti-interference ability, high reproducibility and long-term stability.

Green sonochemical synthesis and fabrication of cubic MnFe2O4 electrocatalyst decorated carbon nitride nanohybrid for neurotransmitter detection in serum samples

“… Electrode LOD (µM) Sensitivity (µA µM −1 cm −2 ) Linear range/(µM) Ref. GR-FeTSPc/CFME 0.02 2.15 0.05–60 [38] rGO-Ag 2 Se 29.6 0.5 0.1–15 [39] Fe 3 O 4 –CNT–poly(BCG) 0.08 1.72 0.5–100.0 [40] PDMS@cZIF 0.03 2.45 1.0–60 [41] MnO 2 -GR 0.01 4.92 0.1–400 [42] SWCNT 32 0.919 0.1–100 [43] Carbon sphere 700 1.71 40–350 [44] Reduced graphene 32 5.26 1.0–100 [45] MWCNT/CHT 50 8.16 0.05–16 [46] MWCNT/Ni/Zn 118 5.38 0.006–62.8 [47] CNT/CHT/p-ABSA 8 4.26 0.1–522.6 [48] MnFe 2 O 4 /GCN 0.0031 19.377 0.025 – 909.12 This work GR-FeTSPc = graphene-iron-tetrasulfophthalocyanine, rGO-Ag 2 Se = reduced graphene oxide-silver selenide, Fe 3 O 4 –CNT–poly(BCG) = Fe 3 O 4 - multiwalled carbon nanotubes- ...…”

Metal-Oxide Based Nanomaterials: Synthesis, Characterization and Their Applications in Electrical and Electrochemical Sensors

“…Regarding serotonin (SE) detection, MnO 2 nanoparticles have been anchored on graphene (GR) support, yielding MnO 2 -GR composite with a large surface area, improved electron transport, high conductivity and numerous channels for rapid diffusion of electrolyte ions [ 133 ]. Indeed, even if MnO 2 is one of the most promising transition MOX for electrochemical applications due to its non-toxicity, environmental compatibility and low cost [ 134 , 135 ], it is characterized by relatively poor electrical conductivity.…”

“…Recently, Lavanya et al [ 133 ] synthesized a MnO 2 -GR composite by the microwave irradiation method and fabricated an electrochemical sensor for detection of serotonin (SE) (see Figure 14 ). Microwave heating increases the rate of certain chemical reactions by several folds when compared to conventional heating.…”

Transition metal oxide based non‐enzymatic electrochemical sensors: An arising approach for the meticulous detection of neurotransmitter biomarkers

“…A much improved LOD was obtained by the anchoring of MnO 2 nanoparticles on graphene by Nehru et al Here, the formed mesh-like structure possessed an increased surface area with a large number of channels that can facilitate the diffusion of analyte for a better activity. [142] SWV studies revealed a very low detection limit of 10 nM in a linear range of 0.1-800 µM. Some of the other conductive substrates of interest are conductive polymers, such as chitosan and carbon nanotube (CNT).…”