Electrochemical sensing of serotonin by silver decorated polypyrrole nanoribbon based electrode synthesized by sodium cholate as soft template

Abnormal concentration of serotonin (ST), an important neurotransmitter present in the human body, causes multiple physiological disorders and diseases. However, precise and sensitive electrochemical measurement of serotonin, especially in low concentrations is troublesome due to electrode fouling and presence of interferent molecules with identical oxidation potential. So, the surface of the working electrode needs suitable modification for fast, precise, selective, and sensitive determination of serotonin. Here, we demonstrate the fabrication of a polypyrrole (PPY) nanoribbon based nanocomposite decorated with Ag metal (PPY-Ag) to be used as working electrode for electrochemical sensing of serotonin. Several batches of PPY-Ag nanoribbons were synthesized by varying the Ag weight fraction. The sample containing similar to 6 wt% Ag showed the lowest charge transfer resistance as measured by Electrochemical impedance spectroscopy (EIS) and was used for electrochemical sensing of Serotonin. The sensing measurements performed using differential pulse voltammetry (DPV) revealed a linear dependence of the current with concentration of serotonin and the limit of detection value as low as 0.01 nM. The PPY-Ag based electrochemical sensor also showed very good selectivity to serotonin when tested in presence of dopamine (DA), uric acid (UA), and glucose along with long durability making it a very good alternative as a low cost electrochemical sensor for serotonin.

Automated summary

A polypyrrole (PPY) nanoribbon based nanocomposite decorated with Ag metal (PPY-Ag) was successfully fabricated as a working electrode for electrochemical sensing of serotonin. The electrode showed fast, precise, selective, and sensitive determination of serotonin with a limit of detection as low as 0.01 nM.