A durable, stretchable, and disposable electrochemical biosensor on three-dimensional micro-patterned stretchable substrate

Stretchable and disposable electrochemical biosensors as a new immunosensing platform are of great interest for the detection of biomarkers from body fluids including tears, interstitial fluids, sweat, or wound fluids. However, realization of such stretchable electrochemical biosensors has been limited by hurdles of obtaining electrochemical electrodes with high sensitivity, stretchability, and durability under mechanical deformation. Herein, a durable, stretchable, and disposable electrochemical biosensor fabricated by forming thermally evaporated Au working and counter electrodes and a stencil-printed Ag/AgCl reference electrode on a three-dimensional, micro-patterned stretchable substrate with curvilinearly connected bumps and valleys for efficient stress relief under stretching is reported. As an example of target biomolecule, tumor necrosis factor-α (TNF-α) cytokine in human serum ranging from 100 fM to 100 nM, a wound healing parameter, was detected using TNF-α antibody as a probe. The results show high stability of the sensing signal indicating minimal stretch-induced artefacts under a stretched state up to 30% and twisting. The device is also mechanically and electrochemically stable after cyclic stretching at 30% elongation. The device holds great potential for further integration into a body-attachable immunosensing platform, which is promising for the immunodetection of biomarkers in a wearable format.