(Invited) Point-of-Care Diagnostics with Inkjet-Printed Microchips

Multi-layer inkjet printing is applied to prepare microchips that consist of up to eight three-electrode sensors comprising a carbon nanotube (CNT) working electrode, a silver/silver chloride quasireference electrode and a CNT counter electrode. Optionally, the sensors contain micro-wells to measure sample volumes as small as 50 μL. The implementation of inkjet printing allows the flexible design and highly reproducible fabrication of batches of various electrode shapes and dimensions. The usage of CNTs as standalone working electrodes results in electroanalytical sensors with reliable and superior electrochemical response compared to tested commercial carbon paste electrodes. The sensors can be used at least up to 20 times, e.g., based on an immunoassay based strategy, or in a disposable way, e.g., when measuring in complex matrices such as blood. A gold ink is applied as alternative working electrode material. The printed sensors can be used with compact multichannel potentiostats that are suitable for point-of-care diagnostics.