Porphyrin-functionalized glutathione-Ti3C2 MXene quantum dots for enhanced electrochemiluminescence and sensitive detection of copper ions

Ti3C2 MXene quantum dots (MQDs) have recently gained considerable attention as promising emerging nanomaterials for biosensing applications. However, it is still in the infancy of research on the functionalisation of Ti3C2 MQDs to improve their properties. This work synthesised glutathione (GSH)-modified MQDs by hydrothermal method and functionalised them with porphyrin (TMPyP4), resulting in porphyrin-functionalised GSH-Ti3C2 MXene quantum dots (MQDs-TMPyP4) nanocomposite with enhanced electrochemiluminescence (ECL) properties. The lack of selectivity of MQDs and the weak luminescence intensity of ECL have been solved, expanding the method for developing materials with enhanced ECL properties. Cu2+ was found to quench the ECL luminescence of MQDs-TMPyP4, which is valuable for detecting copper ions. Consequently, we constructed a sensitive “Signal on–off” biosensor for Cu2+ detection. The biosensor demonstrated a sensitive response to copper ions within the concentration range of 10 nM to 10 μM, with an impressively low detection limit of 3.22 nM. Additionally, the biosensor exhibited good stability and selectivity. The ECL biosensor performed well and provided an efficient and ultra-sensitive method for detecting Cu2+.