R. de la Rica, A. Alba-Patiño, C. Adrover, S.M. Russell
Balearic Islands Health Research Institute (IdISBa),
Keywords: sepsis, biosensor, nanoparticles, digital health, augmented reality, pathogen, biomarker, procalcitonin, smartphone, origami
Summary:Sepsis, a life threatening multiorgan dysfunction caused by a dysregulated host response to infection, is the cause of death of more than 6 million people around the world every year. It is the most expensive condition to treat in hospitals in the US with a total cost of US$24 billion per year. The poor prognosis associated with sepsis could be greatly improved by expediting the diagnosis so that high-risk patients received life-saving treatments as soon as possible. This requires new diagnosis tools for the rapid detection of infection biomarkers and pathogens at the point of care. Our laboratory has developed several detection platforms under the project name B-SMART with the aim of monitoring sepsis in hospital settings. B-SMART is based on combining three areas of expertise: the manufacture of paper-based biosensors, the fabrication of bioengineered nanoparticles, and the development of smartphone apps for color detection with an augmented reality user interface. Paper is an ideal substrate for developing biosensors for diagnosis because it is inexpensive, light and easily eliminated by incineration . Gold and iron oxide nanoparticles modified with biomolecules allow us to generate robust colorimetric signals that can be read with our smartphone apps [2-3]. Combining these strategies we have developed the first paper-based assay with built-in reservoirs in a single piece of paper for the rapid detection of bacteria. This assay only requires folding a piece paper following a simple set of instructions in order to generate colored spots that are quantifiable with a smartphone. In the context of sepsis these disposable biosensors can be used to identify the pathogen responsible for an infection rapidly, which will help clinicians prescribe personalized antimicrobial treatments. We have used a similar approach in order to detect procalcitonin (PCT), a widely used biomarker for diagnosing and monitoring sepsis, at different concentrations. In this detection platform the smartphone app was programmed to display a semaphore displaying a green light when PCT is lower than 2 ng mL-1, an orange light when it is higher that this value, and a red light when PCT is found above 10 ng mL-1. The easy assay procedure and user-friendly interface afforded by the app make this approach suitable for stratifying patients during triage at emergency departments so that those at high risk of suffering sepsis can be prioritized and treated by specialists as soon as possible. In summary, B-SMART comprises technologies that combine fully integrated, easy-to-use assays in a disposable piece of paper with user-friendly apps that enable quantification with the ubiquitous smartphone. These features make our findings easily translatable to clinical settings where they could be implemented at low cost.  ACS Sensors 2017, 2, 848.  Sensors and Actuators B: Chemical 2018, 270, 327.  ACS Sensors 2018, 3, 1712.