Simultaneous quantitative detection of hematocrit and hemoglobin from whole blood using a multiplexed paper sensor with a smartphone interface

Abstract

We report a highly accurate single-step label-free testing technology for simultaneous and independent hematocrit (Hct) and hemoglobin (Hb) level detection from a drop of whole blood by deploying a disposable...

Development of a Paper-based Hematocrit Test and a Lateral Flow Assay to Detect Critical Fibrinogen Concentrations Using a Bottom-Up Pyramid Workflow Approach

“…A sandwich assay is commonly used for big molecules like antibodies or proteins, while a competitive assay is used for small molecules or peptides. 37 In our case, a sandwich assay was selected to detect fibrinogen with a molecular weight of around 340 kDa. The detection pad, usually a nitrocellulose membrane, efficiently binds proteins.…”

“…In addition, the most appropriate assay format, such as sandwich or competitive, needs to be selected. A sandwich assay is commonly used for big molecules like antibodies or proteins, while a competitive assay is used for small molecules or peptides . In our case, a sandwich assay was selected to detect fibrinogen with a molecular weight of around 340 kDa.…”

“…Consequently, a higher hematocrit means a lower volume of plasma passing the detection zone, which ultimately affects the result. For a coagulation assay, Li et al reported that the result is affected by the blood’s hematocrit and therefore developed a lateral flow device to determine the hematocrit. , In addition, paper-based devices have been reported, showing a linear correlation between a blood’s hematocrit and travel distance in a wax-printed channel. , Other developed PoC methods for hematocrit measurement include portable smartphone-based analytical platforms , or a portable centrifugal device . Thus, when fibrinogen is measured at a fixed blood volume, the sample’s hematocrit should be taken into account.…”

A smartphone-integrated low-cost, reagent-free, non-destructive dried blood spot-based paper sensor for hematocrit measurement

“…[12][13][14] Paper is predominantly used as a substrate for a DBS due to its multiple advantages, including low cost, capillary ow, biocompatibility, hydrophilicity, and ubiquitous availability with various pore sizes. 15,16 Several strategies are described in the literature to measure the Hct from a DBS extract, e.g., via measurement of potassium ions, 17 hemoglobin, 18 or lipids. 19 While these methods have demonstrated the capability to measure blood Hct, they rely on mandatory blood spot extraction (a destructive procedure) and elution stages to dissolve dried blood spots in a solvent before evaluating their Hct value.…”

“…12–14 Paper is predominantly used as a substrate for a DBS due to its multiple advantages, including low cost, capillary flow, biocompatibility, hydrophilicity, and ubiquitous availability with various pore sizes. 15,16 Several strategies are described in the literature to measure the Hct from a DBS extract, e.g. , via measurement of potassium ions, 17 hemoglobin, 18 or lipids.…”