IrO2 nanoparticles-doped bacterial cellulose as a paper-based platform for optical detection of dopamine

Abstract

Paper-based sensors including different indicators are attractive to many scientists because they can be used in many different fields. Due to their visual interpretability and ease of use, a large number of paper-based sensors have been created as competitors to traditional detection methods. In particular, the application of nanomaterials with different strategies to paper-based biosensors can provide an enhanced colorimetric readout for selective and sensitive detection. Among them, the numerous hydroxyl groups on IrO₂ nanoparticles (IrO₂NPs) surface made it easier for organic molecules to be adsorbed, leading to optical change of IrO₂NPs in the presence of biologically important molecules as analyte. In this study, a paper-based optical sensor platform was obtained using bacterial cellulose (BC) doped with IrO₂NPs. The IrO₂NPs-doped BC (IrO₂NPs@BC) was cut into circular pieces (spot) for easily handling and used for dopamine detection. The dopamine sensor showed linear response in a concentration range of 0.30 µM to 10 µM in solution, while it revealed a linear range of 0.60 mM to 2.5 mM in paper-based platform. Limit of detection (LOD) and limit of quantification (LOQ) values were determined to be 0.107 µM and 0.325 µM in solution media, and to be 0.479 mM and 1.45 mM for the proposed paper-based optical sensor platform, respectively.