Smartphone-Based Chemiluminescent Origami µPAD for the Rapid Assessment of Glucose Blood Levels.

Donato Calabria,Elisa Lazzarini,Andrea Pace,Mara Mirasoli,Massimo Guardigli,Martina Zangheri,Ilaria Trozzi

doi:10.3390/bios11100381

Donato Calabria, Elisa Lazzarini + Show 5 more

Open Access

https://doi.org/10.3390/bios11100381

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Journal: Biosensors	Publication Date: Oct 9, 2021
Citations: 21	License type: CC BY 4.0

Affiliation: University of Bologna

Abstract

Microfluidic paper analytical devices (µPADs) represent one of the most appealing trends in the development of simple and inexpensive analytical systems for diagnostic applications at the point of care (POC). Herein, we describe a smartphone-based origami µPAD for the quantitative determination of glucose in blood samples based on the glucose oxidase-catalyzed oxidation of glucose leading to hydrogen peroxide, which is then detected by means of the luminol/hexacyanoferrate(III) chemiluminescent (CL) system. By exploiting the foldable µPAD format, a two-step analytical procedure has been implemented. First, the diluted blood sample was added, and hydrogen peroxide was accumulated, then the biosensor was folded, and a transport buffer was added to bring hydrogen peroxide in contact with CL reagents, thus promoting the CL reaction. To enable POC applicability, the reagents required for the assay were preloaded in the µPAD so that no chemicals handling was required, and a 3D-printed portable device was developed for measuring the CL emission using the smartphone’s CMOS camera. The µPAD was stable for 30-day storage at room temperature and the assay, displaying a limit of detection of 10 µmol L−1, proved able to identify both hypoglycemic and hyperglycemic blood samples in less than 20 min.

Highlights

Biosensors that fulfill the ASSURED World Health Organization criteria have become widely accepted as the benchmark for an ideal test that can be used for diagnostic purposes at the point of care (POC)
Level 4 had the role of preventing premature contact between the hydrogen peroxide produced in level 3 and the CL reagents in the lower levels when the biosensor is folded before insertion into the holder
The buffer migrated by capillarity toward the lower levels of the biosensor carrying the hydrogen peroxide produced in level 3 and dissolving the CL reagents loaded in levels 5 and 6

Summary

Introduction

Biosensors that fulfill the ASSURED (affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free, and deliverable to end-users) World Health Organization criteria have become widely accepted as the benchmark for an ideal test that can be used for diagnostic purposes at the point of care (POC). Two additional criteria were proposed to yield the REASSURED concept, where R indicates real-time connectivity and E stands for ease of specimen collection and environmental friendliness [1]. In this context, one of the most appealing trends in the development of simple and low-cost analytical systems that can be employed by unskilled users is represented by microfluidic paper-based analytical devices (μPADs) [2,3,4,5,6]. The three-dimensional (3D) μPADs, such as the foldable μPADs that exploit the origami principle (i.e., implementing flow and mixing control by folding/unfolding the paper device), enable the execution of complex multistep analytical protocols that require a series of sequential operations [7]

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