PHsense - Conceção e desenvolvimento de sensores baseados em microfluxo como dispositivos de utilização fácil e descartáveis para monitorizar indicadores de Saúde Pública numa perspetiva Saúde Global

The proposed project aims to design, develop, and study novel microfluidic analytical devices for on-hand public health biomarkers assessment in natural waters and biological fluids of non-invasive collection, in a One Health approach. The idea is to produce fast-response and accurate sensor devices to enable reliable and on-time results, making possible effective public health monitoring. The possibility to provide a real-time response, using disposable, self-readable microfluidic devices applied to both environmental and biological samples is a breakthrough for understanding public health potential issues, thus enabling an efficient course of action. The chosen approach is to explore the concepts of microfluidic paper-based analytical devices (μPADs) and polymer inclusion membranes (PIMs) to develop innovative sensor devices for quantification of the chosen biomarkers. The public health biomarkers (nitrate, iodine, aluminum, and glyphosate) were selected based on their transversal profile, from natural waters and food sources to human health issues. Nitrate, a commonly used fertilizer, can accumulate in humans because of the high content in the consumption of water as well as vegetables. Its accumulation is a health issue and, by minimizing the iodine assimilation, emphasizes iodine deficiency disorders (IDD). Iodine has been a pivotal health indicator through urine analysis for many years and, by developing an on-hand sensor will enable a faster assessment. The combination of the iodine content with the nitrate determination will facilitate understanding the dynamic of iodine assimilation and why some solutions, namely the iodization of salt, appear to fall short in eliminating IDD. Aluminum determination in water sources for human consumption and its transference to the human body has been reported to have a direct relation with the increase of Alzheimer condition. Its determination in both water samples and saliva and urine will help to establish a correlation. Although the use of glyphosate as a herbicide is under discussion to be forbidden, it is still being employed; so, monitoring its leaching to water sources is vital. Considering that glyphosate is not only toxic but also carcinogenic, our aim to monitor its presence in human saliva and urine is a robust contribution to tackling a potential public health hazard. Biological fluids of non-invasive collection, namely saliva and urine, are ideal target samples, as their composition can be related to the serum content and their composition is affected by specific and identifiable causes. The μPADs will be a novel approach to assessment/screening methods displaying advantages like their hand size and low cost. Colorimetric detection was chosen as the most suitable technique to combine with μPADs due to its simplicity and compatibility with relatively low-cost and portable detection systems, such as smartphones and scanners. The portability of the hand-sized devices and their simplicity of operation make the proposed devices ideally suited for unskilled operators. This feature is highly appropriate for use in rural areas and field campaigns in developing countries.