Squarate-Based Metal-Organic Frameworks for Highly Selective and Sensitive Electrochemical Sensing of Dopamine

Dopamine (DA) is an important catecholamine neurotransmitter associated with learning, depression, addiction, and memory loss with simultaneously coordinating movement and reward-associated behavior. It is very important to design highly effective and sensitive sensors for the detection of DA. However, it remains a challenge for detecting DA to obtain selectively and rapidly sensing materials. In this work, we chose octahedral-coordinated squarate-based MOFs with dense Lewis active centers as electrode materials to investigate the electrochemical performance of dopamine oxidation. The multiple ligand functional groups in squarate-based MOFs enable noncovalent interaction with diols, amines, and phenyl groups of DA molecules through electrostatic, H-bonding, and/or pi-pi stacking interactions. The modified electrode exhibits a wide linear current response range between 2 mu M and 400 mu M for DA, and the sensor shows significant selectivity and stability. This work enriches the application library of redox-active squarate compounds and can give us a better comprehension of the design and selection of electrode materials for electrochemical sensing and even more catalysis-related research.