Preparation and performance regulations of ionic cellulose-based glucose semipermeable membranes

The global rise in diabetes is driving increasing demand for electrochemical biosensors, in which the outer membrane is critical for long-term stability. In this paper, we report a new class of semipermeable membranes for electrochemical biosensors based on anionic, cationic, and zwitterionic cellulose graft copolymers. These membranes achieve glucose permeability coefficient (P) of ∼10^-7 cm²/s, which is one order of magnitude higher than the membranes prepared from Nafion®-based membranes prepared under comparable conditions. Moreover, ionic cellulose-based membranes exhibit charge-dependent ion selectivity, in which like-charged ions are electrostatically repelled and blocked. Notably, the zwitterionic membranes uniquely combine complete blocking of both cation and anion permeation with superior protein adhesion resistance. These cellulose-based ionic membranes represent promising candidates for enhancing sensitivity and long-term stability in electrochemical biosensors, particularly for continuous glucose monitoring applications.