Micro additive manufacturing of glucose biosensors: A feasibility study

Flexible electrochemical sensors for measurement and quantification of biomarkers are attracting a great deal of attention in non-invasive medical applications, due to their high mechanical compatibility and conformability with the human body. Realization of the full potential of such novel systems relies heavily on their effective manufacturing. Particularly, there is a need for manufacturing techniques that can realize complex designs, consisting of multiple functional materials which are required for sensor functionality. Among emerging additive manufacturing techniques, Direct-Ink-Writing (DIW), where polymer nanocomposite inks are dispensed through nozzles and deposited with high spatial control, carries a great potential to address this need. Here, we introduce a 3D printed flexible electrochemical biosensor for glucose detection. We show that our biosensor works linearly in glucose solution with a concentration range between 100 and 1000 μM. The sensitivity of glucose biosensor is estimated to be 17.5 nA μM^-1, and the calculated value of the detection limit (S/N = 3) is 6.9 μM. The demonstrated electrochemical performance and surface properties of the printed sensors show the promising advantages of using this technique over the conventional screen printing method. These advantages include higher sensitivity and specificity and, reduced material consumption.