Skip to main content

Self-amplified photonic biosensing platform for microRNA-based early diagnosis of diseases

Periodic Reporting for period 2 - SAPHELY (Self-amplified photonic biosensing platform for microRNA-based early diagnosis of diseases)

Reporting period: 2016-02-01 to 2017-01-31

In today’s point-of-care (POC) market segment, there is an ever-increasing demand for novel and more efficient devices for the early diagnosis of diseases, with a special interest in cancer. According to statistics from the World Health Organization (WHO), each year approximately 7.5 million people around the world die because of this disease. Despite these numbers, the WHO states that most cancer types have high cure rates when detected early and treated according to best practices. Therefore, having early and trustful detection tools for the implementation of preventive mass screening programs is a key factor for reducing cancer mortality rates.
On the other hand, the scientific community has recognised the importance of nanotechnology for the current market, with improved performances and functionalities compared to existing technologies and opening the field of applications from health and energy to environmental issues. Among them, nanophotonic technology is one of the main candidates for the creation of the core transduction elements of future high-performance biosensors since it provides significant advantages such as high sensitivity, compactness and high integration level, shorter time to result, label-free detection, and use of very low sample volumes.
Within this context, the SAPHELY project aims at developing a compact and low-cost POC device based on nanophotonic technology for its application to minimally-invasive early diagnosis, with initial focus in cancer. This POC device will significantly help to reduce the actual costs designated for early diagnosis and to implement mass screening programs, meaning a significant contribution to the improvement of the citizens’ health status and to the sustainability of healthcare systems.
In summary, the main outcomes from the work carried out during Period 2 have been:
- Optimal molecular beacon (MB) capture probes have been designed and experimentally tested for all the miRNA targets selected in the project, demonstrating a good specificity.
- Several potential miRNA extraction protocols have been evaluated in order to later transfer them into a chip format. From this evaluation work, we have been able to select a protocol being much simpler that the others and requiring less processing steps.
- Work in the transference of the miRNA extraction protocol to a chip format has been carried out.
- Additional work on the validation of the miRNA targets has determined that it will be enough with considering 10 miRNA targets for the identification of the 4 cancer varieties considered in the project, instead of the initially planned 20-25 miRNA targets. This will significantly simplify the implementation of the SAPHELY device for the application targeted.
- Working photonic sensing chips fabricated by e-beam lithography (EBL) have been produced. Several problems were faced during this development (e.g. PBG edge not located around 1550 nm, non-sharp PBG edge, breakage of the photonic waveguides, etc.), but we have been able to solve them.
- The process for the transference of the fabrication to NIL has been developed.
- We have been able to immobilize the selected model miRNA systems onto the SOI substrates using LAMI and TEC biofunctionalization approaches, and then to successfully test their recognition performance.
- We have successfully immobilized several MB probes onto the photonic sensing structures in order to perform the miRNA biorecognition experiments. In those experiments, we have been able to make a direct detection of certain miRNA targets using the standalone MB probes as well as to make a self-amplified detection using MB+streptavidin complexes, whose operation principle is equivalent to that for the MB+NP complexes proposed in the project.
- A prototype of the “product-like” version of the SAPHELY readout platform has been developed. This platform is able to perform the optical interrogation of the photonic sensing chips in an automated way and then showing the outcome of the experiment via a graphical user interface.
- The collection of clinical samples has continued during Period 2.
- Exploitation issues of the project have been addressed by elaborating a newer version of the exploitation plan, evaluating the risks associated with the project, creating a technological roadmap, etc.
- Dissemination/communication activities targeting the promotion of the SAPHELY project have been carried out, including the preparation of a promotional video of the project.
The novel nanophotonic-based technology to be developed in the SAPHELY project will allow a more sensitive, robust and selective analysis for improved clinical decisions through an early and fast diagnosis of the disease at a reduced cost, thus opening the door to the effective implementation of high-throughput screening programs. This will lead to better health outcomes, since the proper treatment/response can be applied to the patient in an earlier stage, and will contribute to the sustainability of the health care system by decreasing the expenditure associated with pharmaceutical treatments and with hospitalization. Moreover, this analysis device can also be used for its application in the monitoring and assessment of therapeutic response of a patient, opening the door to the practical implementation of the so-called “personalized medicine”.
SAPHELY optofluidic sensing chip