Ti3C2TxMXene/nitrogen-doped reduced graphene oxide composite: a high-performance electrochemical sensing platform for adrenaline detection.

Herein, Ti3C2Tx MXene/nitrogen-doped reduced graphene oxide (MXene/N-rGO) composite as electrocatalyst was employed to construct a new electrochemical sensing platform for the determination of adrenaline (AD). The MXene/N-rGO was synthesized via a facile one-step hydrothermal method, where ethylenediamine (EDA) acted as reducing agent and nitrogen source. The doped N in rGO serves as a bridge between MXene and rGO through tight hydrogen bonds. Scanning electron microscopy (SEM) shows that large numbers of MXenes with accordion-like morphology were distributed on the surface of N-rGO. The MXene/N-rGO composite displays synergetic catalytic effect for oxidizing AD originating from unique catalytic activity of N-rGO, large surface area and satisfactory conductivity of MXene. These characteristics of composite material lead to a remarkable effect on signal amplification for the detection of AD, with a wide linear range from 10.0 nM to 90.0 μM and a low detection limit of 3.0 nM based on a signal to noise ratio of 3. Besides, the MXene/N-rGO electrode displays good stability, repeatability, and reproducibility. Additionally, the proposed sensor was successfully applied for voltammetric sensing of AD in urine with recoveries from 97.75% to 103.0%.