Development of a Smartphone Based Reader for the Quantitative Analysis of Lateral Flow Assays

Abstract

Smartphones are developing into all-purposes devices. In the present work, the employment/application of smartphones as medical devices in home care and point-of-care (POC) diagnostics are investigated in the analysis of Lateral Flow Assays (LFA). A smartphone-based LFA reader was developed for the quantitative analysis of D-Dimer – a biomarker indicating e.g. thrombotic event or danger of embolism.The proof-of-concept has been shown with multiple smartphones in establishing: (I) Optimal dimensions of the LFA cell of 72.11mm distance of smartphone to D-Dimer test leading to a coefficients of variances (CV) between 0.8% and 4.2%. (II) Inter-device investigations: CVs around 13.5%; a limit of detection (LOD) of 100ng/ml (DDU) D-Dimer. (III) Inter-smartphone investigations: CV about 16%, a limit of detection (LOD) at 66.4ng/ml (DDU). (IV) Calibrations: CV and LOD of three smartphones are comparable to the commercial available LFA reader. Further development to put the multiple smartphone-based LFA reader on the market.

Potential of Point-of-Care and At-Home Assessment of Immune Status via Rapid Cytokine Detection and Questionnaire-Based Anamnesis

“…In principle, LFAs delivered qualitative results, as in (hIL-8 XpressCard), unlike the LFA-AuNPs biosensor [ 5 ], the LFA-CdTe QDs biosensor [ 37 ], and the LFA (Milenia Biotec) IL-6 tests which used densitometry, portable fluorescence reader, and a camera, respectively, to convert the qualitative readouts to quantitative ones. However, the qualitative results delivered by the LFAs are no longer problematic because various smartphones-based solutions [ 66 , 67 , 68 ] were developed to produce quantitative results instead. Ruppert et al [ 66 ] used an iPhone S5 with a simple dark box made from black cardboard and an open-source GNSplex R-package which included the Shiny app to compute concentrations from normalized or standardized intensities with a graphical user interface (GUI) to make the analysis of the image data easy.…”

“…Another smartphone-based LFA reader [ 67 ] was developed by Schneider et al that was competitive with well-established LFA readers: QuickSens 100 (8sens. biognostic GmbH, Berlin, Germany, QuickSens) and the SkanSmart (Skannex AS, Oslo, Norway, SkanSmart).…”