Development of a new electrochemical sensor for serotonin detection based on a manganese(<scp>iii</scp>) porphyrin complex

We report the development of a novel electrochemical sensor for serotonin (5-HT) detection, based on a glassy carbon electrode (GCE) modified with a newly synthesized manganese(III) porphyrin complex (triflato)[(<i>meso</i>-tetra(<i>para</i>-tolylphenyl)porphyrinato)]manganese(III), denoted as [Mn^III(TTP)(SO₃CF₃)]. To the best of our knowledge, this is the first study utilizing this specific complex as an electroactive material for serotonin sensing. The complex was thoroughly characterized by FTIR, Raman, and UV-visible spectroscopy. Key experimental parameters, including the mass percentage of the modifier, pH, and scan rate, were systematically optimized. The electrochemical detection of 5-HT was performed using differential pulse voltammetry (DPV), yielding a limit of detection of 5.3 μM and a linear detection range of 10-250 μM. The modified electrode showed high selectivity toward serotonin in the presence of common interferents such as dopamine, glucose, uric acid, ascorbic acid, NaCl, and KCl. It also demonstrated excellent reproducibility (RSD = 1.34%) and repeatability (RSD = 0.8%). Moreover, the sensor's practical applicability was validated through successful detection of 5-HT in artificial urine samples. The originality of the sensing interface and the promising analytical performance highlight the potential of this platform for clinical diagnostics and neurochemical research.