Real-Time and In-Situ Monitoring of H2O2 Release from Living Cells by a Stretchable Electrochemical Biosensor Based on Vertically Aligned Gold Nanowires

Traditional electrochemical biosensing electrodes (e.g. gold disk, glassy carbon electrode, etc.) can undergo sophisticated design to detect chemicals/biologicals from cells. However, such electrodes are typically rigid and non-stretchable, rendering it challenging to detect cellular activities in real-time and in-situ when cells are in mechanically deformed states. Here, we report a new stretchable electrochemical cell-sensing platform based on vertically aligned gold nanowires embedded in PDMS (v-AuNWs/PDMS). Using H2O2 as a model analyte, we show the v-AuNWs/PDMS electrode can display an excellent sensing performance with a wide linear range of 40 µM - 15 mM and a high sensitivity of 250 mA/cm2/M at a potential of -0.3 V. Moreover, living cells can grow directly on our stretchable high-surface area electrodes with strong adhesion, demonstrating their excellent biocompatibility. Further cell stimulation by adding chemicals induced H2O2, which can be detected in real-time and in-situ by our v-AuNWs/PDMS ...