Anthony P. F. Turner
Biosensors and Bioelectronics Centre, IFM, Linköping University, Linköping S-58183, Sweden. firstname.lastname@example.org www.ifm.liu.se/biosensors
This lecture will consider how the recent emergence of printed bioelectronics can offer new solutions to distributed diagnostics for the maintenance of wellbeing, management of an ageing population, food security and environmental safety.
The adaptation of screen printing for the production of enzyme electrodes proved to be a decisive element in the success of mediated electrochemical devices in the home blood-glucose monitoring market. Until then, biosensors had been wholly hand made, and could not possibly address a market requiring billions of devices a year. Coupled with the use of proprietary mediators and patented capillary-fill designs, machine fabrication of enzyme electrodes enabled the paradigm changing switch to the electrochemical devices that now dominate this market. Today, approximately half of the electrodes used in disposable glucose sensors are screen printed using curable polymer inks, while the remainder are produced using a combination of vapour deposition of thin layers of metal such as palladium, followed by laser ablation to pattern these into individual electrodes. Additional printing steps, drop-on-delivery and /or lamination results in a final sensor, which can cost around 2-6 US cents / strip to make, when produced by the millions. However, it is now timely to challenge our original paradigm of a disposable strip coupled to a pocket-sized meter. Even in bulk, the average meters cost between US$7-10 to manufacture, with some more elaborate versions costing as much as US$90.
So why not print the whole device? All-printed Mn –ZnO batteries can already be made to power microsensors and for other applications such as RFID tags, transdermal drug delivery, cosmetic patches and smart packaging. These are available as commercial products such as the SoftBattery™ from Enfucell (Finland). Monochrome emissive or reflective digital displays can be printed on both paper and plastic and, in keeping with the trend to interface biosensing systems with telecommunication, thin film aluminium or copper antennae are also available. A state-of-the-art combination of these technologies allows us to formulate an all-printed sensing instrument where everything is produced on a simple sheet of PET to form a disposable, credit-card like device. An example of such a working demonstrator resulting from collaboration between Acreo ICT AB and our team at Linköping University is shown below. Analyte concentration can be measured in a few seconds and observed via the printed display, with the device being powered by a printed battery. This platform is being used to develop a range of new products incorporating nanomaterials, principally for medical diagnostics, but also for food safety analysis, environmental monitoring and security applications.
In addition to reviewing the evolution of printing technology in this arena, this talk will explore the multifarious sensing configurations that can be supported by this inexpensive and disposable platform. Graphene-based hybrid structures, unsubstituted phenothiazines and Prussian blue nanoparticles have recently been incorporated into novel sensors for metabolites and physiologically important enzymes. Electrochemical immunosensors have also been formulated using silver nanoparticles and in label-free formats. Gold nanoparticles and nanostructured gold surfaces provide further functional enhancement and smart polymers can add reversibility to affinity systems and modulation to catalytic configurations. Finally, synthetic receptors based on imprinted nanoparticles offer robustness beyond that normally achieved with biological components. The combination of advanced synthetic materials with biologically inspired constituents promises to facilitate a growth in personalised analytical solutions that are widely available to the consumer and that can capitalise on the ubiquitous telecommunications and information systems that are now both widely available and rapidly evolving.
Early Protoype (left) and design (right) for a fully integrated, printed biosensor instrument, resulting from collaboration between Acreo ICT AB and our team at Linköping University.
Turner, A.P.F. (2013) Biosensors: Sense and Sensibility: Chemical Society Reviews 42 (8), 3184-3196:http://xlink.rsc.org/?doi=C3CS35528D
2013. 1- p.
Advanced Materials World Congress (AMWC 2013), 16-19 September 2013, Cesme, Izmir, Turkey