Spectroscopic platform for the classification of pathological states

Abstract

In recent years, the application of microfluidic paper-based analytical devices (PADs) has seen a tremendous growth on the diagnostic industry. It is considered to be a highly promising class of point-of-care (POC) diagnostic tests and represents a multibillion-dolar market on its own. This development was motivated by the combination of unique properties of paper-based materials, which includes its simplicity, relative accuracy, fast results, low price and user friendliness. This technology has been used not only in the academic context but also to support a wide range of commercial applications including glucose tests, pregnancy tests, monitoring and testing of cardiac panels in emergency conditions, infectious disease screening, cancer marker screening and drugs abuse testing. This thesis aims at exploring a new approach for combining paper-based analytical devices with a NIR portable spectrometer, with particular focus on: i) designing compact test platforms that are easier to use and handle; and ii) achieve classification and quantification results for aqueous solutions, with low and high viscosity properties. In order to achieve the platform with the properties indicated above, it was necessary to combine several components in a single orchestrated architecture. To pave the way for the development of this project, this work provides: i) a comprehensive study of paper analytical devices; ii) a background theory of NIR spectroscopy and chemometrics; iii) presents the development of the multilayer test strip with an integration in the final embodiment; and, finally, iv) describes the results of the engineered workflow. Experimental results using the final embodiment combined with a prototype platform that was designed to serve as proof-of-concept for the applicability of the envisioned setup in low viscosity solutions have shown promising results in classification and quantification of glucose and wine diluted solutions. The application of a slightly different PAD, altered in the alpha layer, have shown surprising results on blood samples, preserved with EDTA for a blood count analysis. The integrated system was able to classify different blood samples and also quantify crucial parameters as hemoglobin and erythrocytes, when compared to the gold standard technology.

Date of Award	27 Jun 2018
Original language	English
Awarding Institution	Universidade Católica Portuguesa
Supervisor	António Silva Ferreira (Supervisor)