Natural Leukocyte Membrane-Masked Microelectrodes with an Enhanced Antifouling Ability and Biocompatibility for In Vivo Electrochemical Sensing

Probing chemical information in the central nervous system is essential for understanding the molecular mechanism of brain function. Electrochemistry with tissue-implantable carbon fiber electrodes (CFEs) provides a powerful tool for monitoring the dynamics of neurochemicals in a subsecond time scale; however, the implantation of CFEs into brain tissue immediately causes the nonspecific adsorption of proteins on electrode surfaces. This process can dramatically impact the performance of the electrochemical method in terms of reduced sensitivity and accuracy. Herein, we report a strategy to minimize the electrode biofouling by masking CFEs with leukocyte membranes (LMs). We find that the LM masking endows CFEs with a highly hydrophilic surface that gains a high resistance to nonspecific protein adsorption. The electrode reactivity to target molecules decreases by a small degree due to the membrane coating, but the sensitivity loss of the LM-masked CFEs is greatly lessened even after in vivo implantation for 8 h. This study offers a new method of microelectrode modification by natural cell membranes for sustained sensing performance during long-term in vivo analysis.