Jump to main content
Jump to site search

Issue 5, 2021
Previous Article Next Article

A novel vertical flow assay for point of care measurement of iron from whole blood

Author affiliations


Disorders in iron metabolism are endemic globally, affecting more than several hundred million individuals and often resulting in increased rates of mortality or general deterioration of quality of life. To both prevent and monitor treatment of iron related disorders, we present a point of care medical device which leverages a simple smartphone camera to measure total iron concentration from a finger-prick sample. The system consists of a smartphone and an in-house developed app, a 3D printed sensing chamber and a vertical flow membrane-based sensor strip designed to accommodate 50 μl of whole blood, filter out the cellular components and carry out a colorimetric chelation reaction producing a colour change which is detected by our smartphone device. The app's accuracy and precision were assessed via comparison of the mobile app's RGB output to a reference imaging software, ImageJ for the same colorimetric sensing strip. Correlation plots resulted in slopes of 0.99 and coefficient of determination (R2 = 0.99). The device was determined to have a signal to noise ratio >40 and a mean bias of 2% which both indicate high analytical accuracy and precision (in terms of RGB measurement). The smartphone device's iron concentration readout was then studied using an extensively validated laboratory developed test (LDT) for iron detection, which is an optimized spectrophotometry-based technique (this is considered the gold standard for iron quantification among LDTs). In comparison of the smartphone-based technique with the gold standard LDT, a calibration slope of 0.0004 au μg−1 dL−1, a correlation plot with slope of 1.09 and coefficient of determination (R2) of 0.96 and a mean bias of 5.3%, our device can accurately measure iron levels in blood. With detection times of five minutes, fingerpick sample and sensor cost less than 10 cents, the device shows great promise in being developed as the first ever commercial device for iron quantification in blood.

Graphical abstract: A novel vertical flow assay for point of care measurement of iron from whole blood

Back to tab navigation

Article information

07 Dec 2020
04 Feb 2021
First published
09 Feb 2021

Analyst, 2021,146, 1633-1641
Article type

A novel vertical flow assay for point of care measurement of iron from whole blood

M. Serhan, D. Jackemeyer, K. Abi Karam, K. Chakravadhanula, M. Sprowls, P. Cay-Durgun and E. Forzani, Analyst, 2021, 146, 1633
DOI: 10.1039/D0AN02351E

Social activity

Search articles by author