In situ synthesis of gold nanoparticle on MIL-101(Cr)-NH2 for non-enzymatic dopamine sensing

In this paper, MIL-101(Cr)-NH2 was firstly prepared hydrothermally, and then the Au/MIL-101(Cr)-NH2 composites were synthesized by in-situ growth of highly dispersed Au through electrostatic interaction. Moreover, a DA electrochemical sensing method was established based on Au/MIL-101(Cr)-NH2. The morphologies and structure of the sensor material were researched by scanning electron microscopy, transmission electron microscopy, X-ray powder diffractometer, infrared spectrometer, and N2 adsorption-desorption, which proved that the Au nanoparticles were uniformly distributed on porous MIL-101(Cr)-NH2. Electrochemical studies indicated that the established DA electrochemical sensing method based on Au/MIL-101(Cr)-NH2/GCE had a satisfactory detection limit of 9.6 nmol·L−1, the linear range was 0.3–288.8 μmol·L−1, and the sensitivity was 251.6 μA (mmol·L−1)−1 cm−2. These results demonstrated that Au/MIL-101(Cr)-NH2 is an effective electrochemical sensing modification material.