An HRP-based amperometric biosensor fabricated by thermal inkjet printing

Direct inkjet printing of a complete and working amperometric biosensor for the detection of hydrogen peroxide, based on horseradish peroxidase (HRP), has been demonstrated. The device has been realized with a commercial printer. A thin layer of PEDOT:PSS, which was in turn covered with HRP, was inkjet printed on top of an ITO-coated glass slide. The active components of the device retained their properties after the thermal inkjet printing. The whole device has been encapsulated by means of a selectively permeable cellulose acetate membrane. The successful electron transfer between the PEDOT:PSS covered electrode and the enzyme has been demonstrated, and the biosensor evidenced very good sensitivity, in line with the best devices realized with other techniques, and a remarkable operational stability. This result paves the way for an extensive application of "biopolytronics", i.e. the utilization of conductive/semiconductive polymers and biologically active molecules to design bioelectronic devices using a common PC, and exploiting normal commercial printers to print them out. © 2007 Elsevier B.V. All rights reserved.