NO2-functionalized metal–organic framework incorporating bimetallic alloy nanoparticles as a sensor for efficient electrochemical detection of dopamine

Abstract

Abnormal levels of dopamine (DA), a critical neurotransmitter, can lead to various neurological disorders. A selective and sensitive method for detection of DA is therefore required for early diagnosis of such diseases. Herein, we report an approach to sensitive detection of DA using a metal–organic framework incorporating bimetallic alloy nanoparticles (AgPd@Zr-MOF). The as-synthesized MOF was characterized using different physicochemical techniques. The excellent DA sensing abilities of the fabricated material can be attributed to the high specific surface area and enormous number of electroactive sites. The electrochemical features and catalytic efficiency of a AgPd@Zr-MOF-modified glassy carbon electrode were investigated using electrochemical impedance spectroscopy, cyclic voltammetry, linear sweep voltammetry, and square wave voltammetry. The fabricated sensor exhibits a limit of detection of 0.1 μM, a linear DA concentration range of 2–42 μM, and a sensitivity of 10.26 μA μM−1 cm−2. The applicability of the fabricated sensor was tested in human urine and dopamine injection samples. The results of our study could lead to methods for the detection of other neurotransmitters in the near future.