Hand-held colorimetry sensor platform for determining salivary α-amylase activity and its applications for stress assessment
Journal
Sensors (Switzerland)
Journal Volume
19
Journal Issue
7
Date Issued
2019
Author(s)
Abstract
This study develops a hand-held stress assessment meter with a chemically colorimetric strip for determining salivary �\-amylase activity, using a 3,5 dinitrosalicylic acid (DNS) assay to quantify the reducing sugar released from soluble starch via �\-amylase hydrolysis. The colorimetric reaction is produced by heating the strip with a mini polyester heater plate at boiling temperature to form a brick red colored product, which measured at 525 nm wavelength. This investigation describes in detail the design, construction, and performance evaluation of a hand-held �\-amylase activity colorimeter with a light emitted diode (LED) and photo-detector with built-in filters. The dimensions and mass of the proposed prototype are only 120 �� 60 �� 60 mm3 and 200 g, respectively. This prototype has an excellent correlation coefficient (>0.995), comparable with a commercial ultraviolet�Vvisible spectroscope, and has a measurable �\-amylase activity range of 0.1�V1.0 U mL?1. The hand-held device can measure the salivary �\-amylase activity with only 5 �gL of saliva within 12 min of testing. This sensor platform effectively demonstrates that the level of salivary �\-amylase activity increases more significantly than serum cortisol, the other physiological stressor biomarker, under physiologically stressful exercise conditions. Thus, this work demonstrates that the hand-held �\-amylase activity meter is an easy to use and cost-effective stress assessment tool for psychoneuroendocrinology research.
SDGs
Type
journal article