Synthesis of Spherical Nanoflower-Shaped Ti3C2Tx MXenes for Application in the Label-Free Colorimetric Sensing of Silver Ions

Abstract Since their discovery, MXenes have been exclusively known as 2D materials. In this study, we demonstrated a wet chemical method for the synthesis of spherical nanoflowered Ti3C2Tx MXene and its application in the design of a colorimetric sensor. The proof-of-principle concept was demonstrated for a label-free colorimetric sensor based on the instantaneous reduction of silver ions (Ag+) on the surface of hydrophilic spherical nanoflower-shaped Ti3C2Tx MXene colloidal suspension. The colorimetric changes induced by Ag+ were recorded using a UV-Vis spectrophotometer, showing a concentration-dependent response selective for Ag+ among the tested ions. The developed spherical nanoflower-shaped MXene-based analytical system showed a linear response to Ag+ over the concentration range of 2−100 μM, with detection and quantification limits of 1.64 and 5.48 μM, respectively. These results demonstrate the potential of morphology-controlled Ti3C2Tx MXenes as simple, fast, label-free colorimetric platforms for Ag+ determination in aqueous samples.