Polyserotonin was enzymatically synthesized using Horseradish peroxidase (HRP) as the catalyst. This novel conjugated polymer exhibited good fluorescent properties with significantly higher Stokes shift than its monomer. The enzymatic polymerization eliminated the need for extensive purification of the product (typically necessary for the removal of residual metal catalyst) allowing the product to be naturally fluorescent as synthesized. The reaction was monitored using UV-Vis spectrophotometry and the polymers were characterized using Fluorescence, Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetry. The possibility of using polyserotonin for the detection of nitro-aromatic compounds, including 2,4dinitrotoluene (DNT) and trinitrotoluene (TNT), through fluorescence quenching at parts per million levels in solution has also been demonstrated.