Cancer diseases are a leading cause of death worldwide, caused by the abnormal transformation of cells within the body. The current discovery of circulating tumour markers is today a key element in cancer diagnosis and follow-up, also playing an important role in the early analysis of cancer risk. Tumour markers are biomolecules that are produced by the body in response to or along with cancer growth, and that may be detected in biological samples, such as blood, urine or tissues. Therefore, screening these cancer biomarkers provides information about the stage of the disease, at a faster, non-invasive and low cost way.
Screening cancer biomarkers requires however the development of a suitable technology. This is the main purpose of the FET-Open project Symbiotic, in which a self-powered and self-signalled device is pursued. In this, a biorecognition element is used to detect a given cancer biomarker, while being integrated inside a fuel cell. The fuel cell in turn acts as a power source, and its energy is driven towards an electrochromic cell that generates a colour change. Overall, the energy generated by the fuel cell is dependent on the amount of biomarker present, which in turn determines the intensity of colour change. Then, the colour observed by the user depends on the concentration of the targeted biomarker.
The Symbiotic biosensor has been developed so far to produce a response against small size cancer biomarkers, preferably excreted in urine. In this, the system is tested first to confirm that the fuel cell is generating the necessary energy. Then the sample is incubated in the system for about 30 minutes. It is washed out after, with the fuel that feeds the cell. The presence of the biomarker is identified by the lack of colour or the lower intensity colour appearing in the device.
Current progresses are being made to integrate an all-printed and flexible fuel cell already developed to replace the passive fuel cell of the current set-up.
Schematic representation of the device and the necessary stages of operation.
Proof-of concept of the Symbiotic device operating for an emerging cancer biomarker in prostate cancer. Buffer is system check.
All-printed fuel cell with holder.