Polydopamine Modified Ti3AlC2 MAX Phase Promotes Electrochemical Heavy Metal Detection

Abstract

Environmental pollution, particularly heavy metal ions (HMIs), poses a significant threat to the environment and human health due to its adverse long-term effects. Recently, MXene-based materials have showcased outstanding HMI sensing abilities, owing to their remarkable electrical conductivity, hydrophilicity, and surface tunability. However, it is intriguing to investigate if its precursor MAX phase also possesses such sensing capabilities. In this study, we developed an electrochemical sensing platform by functionalizing the surface of Ti3AlC2 MAX phase using mussel-inspired polydopamine (pDA) (p-MAX) and then applying it onto the glassy carbon electrode (GCE) for HMI detection. The p-MAX modified GCE outperformed both bare and MAX modified GCE in electrochemical performance and exhibited low detection limits of ∼1.43, 2.41, and 2.48 ppb against the individual detection of Cd+2, Pb+2, and Cu+2, respectively, and ∼3.43 and 3.47 ppb against the simultaneous detection of Pb+2 and Cu+2, respectively. Structural and morphological properties of synthesized composites corroborated with the sensing results. Furthermore, the p-MAX modified sensor demonstrated robust performance in detecting HMIs in real samples. The findings of this work open a new direction for the research on chemically engineered MAX phases for HMIs detection.