Understanding the functionality of multiplexed sensors in order to aid design and enhance performance

Abstract

The use of multiplexed paper sensors for health and environmental monitoring applications continues to rise. Multiplexed devices are capable of detecting multiple disease biomarkers or contaminants from a single sample. These devices make testing simpler, faster and at lower cost. However, challenges, such as the misinterpretation of test results, difficulty in signal quantitation and cross reactivity continue to exist. Misinterpretation is often due to the presence of multiple test lines (TLs), especially since the standard is that two lines indicate a positive test result (such as the home pregnancy test). Weak signals exacerbate the problem further, being misinterpreted as false positive or negative signals. In this work and that of others, the signal intensity of TLs on a multiplex lateral flow test were found to reduce the further away it is positioned from the colorimetric reporter element, regardless of the analyte concentration. This implies that the detection/test line placed furthest away on such devices may be at risk of developing a false negative test result. This could have negative consequences when such tests are used to diagnose illnesses or pathogens. This work studies the phenomenon of weakening signal intensities on multiplexed sensors. Little work has been found on this subject matter.