Prussian Blue Nanoparticle Supported MoS₂ Nanocomposites as a Peroxidase-Like Nanozyme for Colorimetric Sensing of Dopamine

An abnormal level of dopamine (DA) is usually related to neurological disorders, including Parkinson's disease. Herein, cubic-shaped, Prussian blue nanoparticle-supported MoS₂ nanocomposites (MoS₂-CPBNPs) were prepared as peroxidase-like nanozymes for the label-free, colorimetric detection of DA. As expected, the as-prepared MoS₂-CPBNPs nanozymes have outstanding peroxidase-like mimicking activity, which can catalyze 3,3',5,5'-Tetramethylbenzidine (TMB) to generate blue, oxidized TMB in the presence of hydrogen peroxide (H₂O₂). DA can inhibit the oxidation of TMB, which causes blue solutions to fade and become colorless. According to this phenomenon, the developed colorimetric sensor can qualitatively and quantitatively analyze DA ranging from 0 to 300 μM with a detection limit of 0.09 μM. In addition, the high recovery and low relative standard deviation for practical DA determination suggested that this colorimetric sensor has potential for application in biological biosensing and diagnostic fields.