Cylindrical electrochemical sensor fabricated by rotated inkjet printing on flexible substrate for glucose monitoring

This paper reports a novel electrochemical glucose sensor fabricated on the flexible cylindrical substrate with bigger working electrode surface by the rotated inkjet printing method to overcome the challenge of hypoglycemia detection in clinics. The rotated inkjet printing technique enables directly patterning microstructures on cylindrical surface which overcomes the limit of the traditional planar micromachining by lithography. (3-Aminopropyl) trimethoxysilane (APTES) and (3-Mercaptopropyl) trimethoxysilane (MPTMS) were employed to modify the flexible cylindrical substrate (polyetheretherketone, PEEK) to promote the surface wettability to avoid the coalescence of adjacent droplets, and to promote the adhesion of metals to PEEK which, in turn, is beneficial to constructing stable and durable microelectrodes on the cylindrical surface. Then a bigger working electrode surface is obtained to improve the sensitivity of the sensor which, in turn, enables the potential for hypoglycemia detection. Both of the structure and the manufacturing process of the proposed glucose sensor are much simpler compared with those of the traditional pin-like enzyme electrode sensor.