Electrochemical laser induced graphene-based oxygen sensor

A fully integrated dissolved oxygen (DO) sensor was fabricated using laser induced graphene (LIG). The LIG was patterned on polyimide (Kapton) film using CO2 laser followed by the electrodeposition of colloidal platinum to form the electroactive sensing area. The sensing area was insulated in an oxygen gas permeable membrane for selective detection of DO. The fabricated sensor demonstrated excellent catalytic activity towards the reduction of oxygen with a sensitivity of 246.66 itA/mMcm2 over a linear detection range of 30 itM to 400 itM. The sensor exhibited a limit of detection (LOD) of 2.4 itM DO and fast response time of 2 s. The LIG-based DO sensor also exhibited good selectivity and stability. The sensor was further evaluated in a cell culture system to monitor DO to maintain cell culture viability. The DO sensor showed good performance in detecting oxygen in fresh medium (82.2 itM), at 80% cell confluency (102.37 itM), and at 100% confluency (93.52 itM). The performance of the DO sensor offers great promise for detecting dissolve oxygen in cell culture systems for biomedical and environmental applications.