The long-term goal of this project is development of a low-cost sensor system that women can use at home on a regular basis to self-monitor weekly or monthly variations of a panel of reproductive hormones in urine. This project will initially target detection of luteinizing hormone (LH), but multiplexed monitoring of multiple hormones is envisioned in future years. The sensing concept will eventually linked to advanced telecommunications technology. The impact of this home-monitoring concept reaches toward the ability to provide life-long monitoring of female reproductive health. The broader impacts move the concept of diagnostics from the detection of an event to the monitoring of biological systems, enabling that transition through inexpensive sensing devices and (ultimately) convergence with existing telecommunications. The broader impacts of this concept also address the value of the medical and scientific information that could be generated for epidemiological purposes. These statistics could be used for national policy and for improving the scientific understanding of the etiology of women?s reproductive pathologies and maladies. The epidemiological statistics could also be of use to the individuals providing the primary data, where successful interventions and therapies tied to an understanding of baseline levels of particular hormones are fed back to the participating population via their own smart phones. Additionally, changes in baseline hormone levels could represent early indicators of disease states, and appropriate mining of this enormous database could result in early intervention, thus reducing healthcare costs.
A new approach to paper-based sensor fabrication is proposed. It will lead to increased functionality without sacrificing simplicity or affordability. The intellectual merit of this proposal lies in the advancement of a sensor design that is not only robust, but also utilizes a quantitative electrochemical detection scheme that is specifically designed to operate on inexpensive paper substrates. Moreover, this platform will achieve a high signal amplification factor without the need for fragile, slow, and media-sensitive enzymes. Maximum possible signal amplification will be achieved by the use of a magnetic field to localize silver nanoparticles bound to magnetic beads at the detection electrode. The electrochemical detection scheme will be optimized to operate in raw human urine. Further intellectual merit derives from the use and study of micron- and nanometer-scale objects in paper fluidic devices. To date, the non-specific adsorption and size exclusion properties of objects in this size range have prevented their widespread use in this context, as they are unable to physically move within a cellulose matrix. The proposed use of hollow channels provides a means to bypass these issues and introduce tried and true biotechnology tools to the world of paper-based sensing (without increasing complexity), potentially opening up a broad range of opportunities in biological analyte detection. By integrating simple slip layers into a multi-level design, another major roadblock in paper-based sensing technology " namely, timing of reactions " will also be overcome. These advances will be combined with a robust, sensitive signal detection and amplification platform and a highly manufacturable production design that consists of stencil-printed carbon electrodes and wax-printed paper folded into the final device configuration.
