Immune State Monitoring by Resilient 3DFG Electrochemical Aptamer-Based Sensor

Immunotherapies such as cytokine therapy regulate cell communication in the tumor environment and activate the innate immune system to fight against malignancies. Hyperactivation of immune system induces cytokine release syndrome which secretes excessive cytokines and leads to severe illness during immunotherapy. Monitoring patients’ cytokine concentration to measure immune state will provide valuable information for immunotherapy dosage guidance. Electrochemical aptamer-based (E-AB) sensors allow real-time, label-free, selective, and accurate detection of cytokines with low limit of detection. However, state-of-art gold electrode E-ABs suffer from voltage-driven desorption and competitive displacement of gold-sulfur thiol bond by thiolated molecules in biofluids. Here, we report an E-AB biosensor based on 3-dimensional fuzzy graphene (3DFG) electrodes, modified with aptamers using robust binding chemistries to enhance the sensitivity and stability of the sensor. Wafer scale plasma enhanced chemical vapor deposition synthesis of 3DFG is optimized to allow a highly controlled graphene flake density. Flake density facilitates fast electron transfer of redox reporter signal upon target binding, thereby improving sensitivity. Covalent bonds to the graphene flakes are used to decrease aptamer desorption. Preliminary data indicates 3DFG E-AB sensors stability post 48-hour continuous square wave voltammetry scans. With improved stability in cytokine detection, resilient 3DFG E-AB sensors have the potential for translational immune state monitoring for long-term <i>in vivo </i>and clinical measurement. Integrating with cytokine therapies, 3DFG E-AB sensors can achieve feedback regulated immunotherapies which prevent side effects and improve efficacy of treatment outcomes.