Developmental validation of a point-of-care, salivary α-amylase biosensor

The translation of salivary alpha-amylase (sAA) to the ambulatory assessment of stress hinges on the development of technologies capable of speedy and accurate reporting of sAA levels. Here, we describe the developmental validation and usability testing of a point-of-care, colorimetric, sAA biosensor. A disposable test strip allows for streamlined sample collection and a corresponding hand-held reader with integrated analytic capabilities permits rapid analysis and reporting of sAA levels. Bioanalytical validation utilizing saliva samples from 20 normal subjects indicates that, within the biosensor's linear range (10-230 U/ml), its accuracy (R(2)=0.989), precision (CV<9%), and measurement repeatability (range -3.1% to +3.1%) approach more elaborate laboratory-based, clinical analyzers. The truncated sampling-reporting cycle (<1 min) and the excellent performance characteristics of the biosensor has the potential to take sAA analysis out of the realm of dedicated, centralized laboratories and facilitate future sAA biomarker qualification studies.