Electrochemical detection of serotonin in banana at green mediated PPy/Fe3O4NPs nanocomposites modified electrodes

This study reports electrochemical detection of serotonin at a screen-printed carbon electrode (SPCE) modified with polypyrrole (PPy), doped with green iron (III) oxide nanoparticles. The synthesized iron (III) oxide nanoparticles is from Callistemon viminalis leaves (Fe(3)O(4)NPsL) and flowers (Fe(3)O(4)NPsF) extract. Modified SPCE-PPy-Fe(3)O(4)NPsL and SPCE-PPy-Fe(3)O(4)NPsF electrodes demonstrated good electrocatalytic activity towards serotonin detection compared to other electrodes studied at high anodic peak current. Fe(3)O(4)NPsL and Fe(3)O(4)NPsF represent iron (III) oxide nanoparticles synthesized from Callistemon viminalis leaves, and flowers extract respectively. The dynamic range for serotonin detection was from 0.007 to 0.1 mu M with 0.021 and 0.020 mu M detection limit (LoD) for SPCE-PPy-Fe(3)O(4)NPsL and SPCE-PPy-Fe(3)O(4)NPsF electrodes respectively. LoD values revealed SPCE-PPy-Fe(3)O(4)NPsF as best electrode while SPCE-PPy-Fe(3)O(4)NPsL had optimal current response towards serotonin and best electrode in terms of stability and simultaneous detection of 100 mM ascorbic acid (AA) and 0.1 mM serotonin (5-HT). In this study, SPCE-PPy-Fe(3)O(4)NPsL and SPCE-PPy-Fe(3)O(4)NPsF have proved promising for assay of serotonin in fruit sample (banana).