An Origami Paper-Based Biosensor for Allergen Detection by Chemiluminescence Immunoassay on Magnetic Microbeads

Abstract

Food allergies are adverse health effects that arise from specific immune responses, occurring upon exposure to given foods, even if present in traces. Egg allergy is one of the most common food allergies, mainly caused by egg white proteins, with ovalbumin being the most abundant. As allergens can also be present in foodstuff due to unintended contamination, there is a need for analytical tools that are able to rapidly detect allergens in food products at the point-of-use. Herein, we report an origami paper-based device for detecting ovalbumin in food samples, based on a competitive immunoassay with chemiluminescence detection. In this biosensor, magnetic microbeads have been employed for easy and efficient immobilization of ovalbumin on paper. Immobilized ovalbumin competes with the ovalbumin present in the sample for a limited amount of enzyme-labelled anti-ovalbumin antibody. By exploiting the origami approach, a multistep analytical procedure could be performed using reagents preloaded on paper layers, thus providing a ready-to-use immunosensing platform. The assay provided a limit of detection (LOD) of about 1 ng mL−1 for ovalbumin and, when tested on ovalbumin-spiked food matrices (chocolate chip cookies), demonstrated good assay specificity and accuracy, as compared with a commercial immunoassay kit.

Glucose Oxidase Activity Colorimetric Assay Using Redox-Sensitive Electrochromic Nanoparticle-Functionalized Paper Sensors

“…The optimal GOx detection time was calculated by the saturation point (time constant, τ) in the kinetic curves (Figure S10a). The saturation time point for each concentration (1, 5, 20, and 40 mg/mL) was 3.00, 3.84, 7.60, and 6.33 min, respectively. Based on this result, the Glu@CPS-based GOx analysis time was set to an average time constant of 5 min (Figure S10b).…”

Paper-based point of care diagnostics for cancer biomarkers

“…However, one of the most widely used approaches is the use of the origami method by folding the paper into 3D stacks and holding it with pre-fabricated clamps. 48 Following fabrication, 3D μPADs are functionalized to enable the flow of samples in a regulated manner toward the detection zone for the analysis of results using detection meters. 20,49 Lee et al showed the effectiveness of 3D μPAD impregnated with HRP conjugated anti-Trx-1 antibody for the detection of breast cancer by targeting thioredoxin-1 with the detection limit of 0-200 ng ml −1 in the blood serum samples within 14 min.…”

Paper-based sensors: affordable, versatile, and emerging analyte detection platforms

“…135 In year 2022, Lazzarini et al created a 3D paper sensor using origami and wax printed ink for the detection of allergens in food sample. 136 It describes a sensor made of origami paper that uses magnetic microbeads to functionalize the paper substrate and conducts a competitive chemiluminescence immunoassay for ovalbumin in food samples. The schematic representation of the sensor as shown below in Fig.…”