Bead-based multiplex detection of dengue biomarkers in a portable imaging device

Abstract

Dengue is one of the most rapidly spreading mosquito-borne viral diseases in the world. Differential diagnosis is a crucial step for the management of the disease and its epidemiology. Point-of-care testing of blood-borne dengue biomarkers provides an advantageous approach in many health care settings, and the ability to follow more than one biomarker at once could significantly improve the management of the disease. Bead-based multiplex technologies (suspension array) can measure multiple biomarker targets simultaneously by using recognition molecules immobilized on microsphere beads. The overarching objective of our work is to develop a portable detection device for the simultaneous measurement of multiple biomarkers important in dengue diagnosis, monitoring and treatment. Here, we present a bead-based assay for the detection of one of the four serotypes of dengue virus non-structural protein (DENV-NS1) as well as its cognate human IgG. In this system, the fluorescent microspheres containing the classification fluorophore and detection fluorophore are imaged through a microfluidic chip using an infinity-corrected microscope system. Calibration curves were plotted for median fluorescence intensity against known concentrations of DENV-NS1 protein and anti-NS1 human IgG. The limit of quantitation was 7.8 ng/mL and 15.6 ng/mL, respectively. The results of this study demonstrate the feasibility of the multiplex detection of dengue biomarkers and present its analytical performance parameters. The proposed imaging device holds potential for point-of-care testing of biomarkers on a highly portable system, and it may facilitate the diagnosis and prevention of dengue as well as other infectious diseases.

Microchip imaging cytometer: making healthcare available, accessible, and affordable

“…A broad area green LED illuminates the specimen plane using a set of aspheric lenses and an excitation filter (Fig. 2(a)) 64 . Experimental results demonstrated that the LED light source provides more uniform illumination across the specimen plane, and therefore permits the multiplex detection of three biomarkers.…”

Advances in multiplex electrical and optical detection of biomarkers using microfluidic devices

“…Yuan et al [ 39 ] developed a portable imaging setup comprising microfluidic chips with an objective lens, prism, filters, and camera for the multiplex detection and quantification of a protein and human IgG related to dengue. Carboxyl-modified magnetic beads encoded with different concentrations of allophycocyanin dye provided unique spectral signatures.…”

Designing electrochemical microfluidic multiplexed biosensors for on-site applications

“…In many circumstances, however, clinical evaluation based on a single biomarker is not enough for adequate diagnostics and therapy monitoring. Multiplexing enables the simultaneous monitoring of multiple analytes and/or samples, which dramatically improves the possibility for diagnosis of many diseases, since detecting multiple biomarkers and their diagnostic correspondence in different biofluids [4] can give us more information about the disease, its status, and treatment [5,6]. Moreover, patients often suffer from several diseases simultaneously (for example, diabetes and gout) and thus, the simultaneous measurement of several biomarkers (glucose and uric acid) from a single drop of body fluid would dramatically reduce the pain and effort of the patients during self-management of their chronic diseases [7,8].…”

“…This can be further extended by the separation into multiple channels [7,11], chambers [14], or wells [15]. Although these possibilities are mostly applied for electrochemical detection, using optical detection via labeling with differently colored dyes is an additional option for multiplexing [6,16]. For the realization of multiplexed biosensors, it is also possible to employ different biorecognition elements, including (monoclonal) antibodies, antigens, enzymes (such as glucose or lactate oxidase), or proteins [5,7,13,14,16].…”

“…Here, either the reaction products can be directly sensed as current or potential in an amperometric or potentiometric method [12] but also different readout techniques like cyclic voltammetry [12], electrochemiluminescence [18], electrochemical impedance spectroscopy [5,14], or surface-enhanced Raman spectroscopy [23] are employed. Another possibility for multiplexed readout is the optical detection using flourescent dyes [6,16,20] or using localized surface plasma resonance (LSPR)-based nanoplasmonic biosensors [24]. Nanoplasmonic sensors can offer high sensitivity, high throughput, label-free, and multiplexed analysis; however, they may suffer from requirement of complex instrumentation and low specificity while working with complex samples.…”