Portable smartphone quantitation of prostate specific antigen (PSA) in a fluoropolymer microfluidic device.

Ana I Barbosa,Poonam Gehlot,Nuno M Reis,Kalpita Sidapra,Alexander D Edwards

doi:10.1016/j.bios.2015.03.006

Abstract

We present a new, power-free and flexible detection system named MCFphone for portable colorimetric and fluorescence quantitative sandwich immunoassay detection of prostate specific antigen (PSA). The MCFphone is composed by a smartphone integrated with a magnifying lens, a simple light source and a miniaturised immunoassay platform, the Microcapillary Film (MCF). The excellent transparency and flat geometry of fluoropolymer MCF allowed quantitation of PSA in the range 0.9 to 60 ng/ml with<7% precision in 13 min using enzymatic amplification and a chromogenic substrate. The lower limit of detection was further improved from 0.4 to 0.08 ng/ml in whole blood samples with the use of a fluorescence substrate. The MCFphone has shown capable of performing rapid (13 to 22 min total assay time) colorimetric quantitative and highly sensitive fluorescence tests with good %Recovery, which represents a major step in the integration of a new generation of inexpensive and portable microfluidic devices with commercial immunoassay reagents and off-the-shelf smartphone technology.

Highlights

Decentralisation of diagnostic testing to near the patient sites is both a trend and a need in clinical diagnostics
In this study we present a flexible smartphone based colorimetric and fluorescence detection system, termed the MCFphone, capable of detecting prostate specific antigen (PSA) from whole blood in the relevant clinical range in 13 min using colorimetric detection and 22 min using fluorescence detection
This favours sensitive immunoassays that combined with short diffusion distances yields a powerful miniaturised and portable point of care (POC) immunoassay concept

Summary

Introduction

Decentralisation of diagnostic testing to near the patient sites is both a trend and a need in clinical diagnostics. Agglutination and lateral flow assays are the most widely used POC immunoassay tests, these formats are usually qualitative or semi-quantitative, lacking both the sensitivity for many important biomarkers and the ability to perform multiplex analysis (von Lode, 2005). This has driven the n Corresponding author at: Department of Chemical Engineering, Loughborough University, Loughborough, LE11 3TU, United Kingdom.

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