A smartphone-enabled colorimetric sensing platform based on Au-decorated Fe3O4 nanoparticles as nanozyme for dual-mode visual monitoring of dopamine hydrochloride

Abstract

The potential risks associated with the use of dopamine hydrochloride (DH) on the quality of meat and poultry products, as well as human health, are examined in this study. A novel approach for the synthesis of Au-decorated magnetic spherical nanoparticles (Fe3O4@Au) is proposed, aiming to develop colorimetric analysis sensors for mobile devices. Notably, this newly developed nanocomposite exhibits inherent peroxidase-like activity, enabling efficient catalysis of the oxidation reaction between the substrate 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and H2O2. The results of the study led to the development of a colorimetric smartphone sensor, known as Color Image Capture, which demonstrated high sensitivity and visual capability in detecting DH. The methodology involved the utilization of a smartphone and hydrogen peroxide in conjunction with a Fe3O4@Au nanocomposite for the quantification of DH. The alteration in color exhibited by the platform was captured using a mobile camera and subsequently analyzed using a smartphone application. The smartphone colorimetric sensor exhibited a limit of detection (LOD) of 0.0722 μmol/L, enabling the quantitative detection of DH within the concentration range of 0.005–0.125 mmol/L. The colorimetric measurement technique demonstrated efficacy in quantifying DH levels in pork samples. The development of innovative catalysts and the implementation of novel methodologies have contributed novel insights into the detection of DH in intricate food and biological matrices.