Carbon nanotube-red blood cell hybrids as high-performance electrochemical sensing platforms for dopamine and uric acid.

Overcoming the inherent limitations of electron transmembrane transfer is a challenge faced by cell-based biosensors. Exploiting conductive nanomaterials to modify cell membranes offers a promising strategy to address this issue. Herein, we report a hybrid system consisting of multiwall carbon nanotubes (MWCNTs) integrated with red blood cells (RBCs), where the MWCNTs serve as artificial electrical conduits across the cell membrane to facilitate electron transmembrane transfer. Consequently, the MWCNT-engineered RBCs (RBC@MWCNTs) hybrids exhibit significantly enhanced electrochemical activity, enabling highly sensitive and selective simultaneous detection of coexisting essential biomolecules dopamine (DA) and uric acid (UA), both of which are involved in diverse physiological processes and pathological pathways. The electrochemical platform achieves the linear detection ranges of 4-400 μM for DA and 2-500 μM for UA, with corresponding detection limits of 0.10 μM and 0.68 μM, respectively. Furthermore, the successful application of RBC@MWCNTs hybrids for the detection of DA and UA in real biological serum samples validates the effectiveness of this membrane modification strategy in overcoming electron transfer limitations for practical bioelectrochemical sensing applications.