Heterogeneously integrated impedance measuring system with disposable thin-film electrodes

• An integrated impedance measuring system with disposable electrodes.
• Reusable CMOS chip for data retrieval from remote control of the thin-film electrodes.
• We performed suspended DNA concentration tests.
• The system shows doubled sensitivity over previous work.
• Providing a new platform for integrated sensor with disposable interfaces.

We propose a novel integrated impedance measurement system with disposable thin-film electrodes. Most modern CMOS-based biosensors use on-chip electrodes to interface between the electronics and biosamples, which forces disposal of the CMOS chip after a few measurements, since most biological reactions are non-reversible. The sensor performance is also limited by the design of on-chip electrodes due to the physical dimensions and the CMOS design rules restrictions. In this work, we extract the electrodes from the silicon chip for relocation onto a low-cost, disposable substrate. This enables reusability of the high-performance CMOS chip, at the same time providing a low-cost route for manufacture of the active thin-film electrodes using large-area processing. The use of disposable thin-film chip also enables customised designed electrodes for different applications, such as extra high sensitivity concentration sensors. In this work, DNA concentration measurements are performed, and it shows a doubling of sensitivity over the previously reported system.