This study explores a smartphone-based spot detection
framework
for glucose in a rapid, simple, and affordable paper-based analytical
device (PAD), which employs machine-learning algorithms to estimate
various glucose concentrations. Herein, two different detection mixtures
were chosen with chitosan (C) and without chitosan (WC) for the color
change analysis. Being a biopolymer, chitosan improves the analytical
performance of PADs when used with a chromogenic agent. Moreover,
the influence of the illumination conditions and camera optics on
the professed color of glucose strips was observed by choosing various
illumination conditions and different smartphones. Hence, this study
focuses on developing a framework for smartphone-based simple and
user-friendly spot-based glucose detection (with a concentration range
of 10–40 mM) at any illumination conditions and in any direction
of illumination. Additionally, the combination of color spaces and
machine-learning algorithms was applied for the signal enhancement.
It was observed that the machine learning classifiers, cubic support
vector machine (SVM) and narrow neutral network show higher accuracy
for the WC samples, which are 92.7 and 92.3%, respectively. The samples
with chitosan show higher accuracy for the linear discriminant and
quadratic SVM classifiers, which are 94.1 and 93.9%, respectively.
Simultaneously, cubic SVM shows ∼93% accuracy for both cases.
In order to assess the performance of the devices, a blind test was
also conducted. This study demonstrates the potential of the developed
system for initial disease screening at the user end. By incorporating
machine learning techniques, the platform can provide reliable and
accurate results, thus paving the way for estimating the accuracy
of the results for improved initial healthcare screening and diagnosis
of any disease.