Development of a Diagnostic Biosensor Method of Hypersensitivity Pneumonitis towards a Point-of-Care Biosensor

Abstract

In spite of a current increasing trend in the development of miniaturized, standalone point-of-care (PoC) biosensing platforms in the literature, the actual implementation of such systems in the field is far from being a reality although deeply needed. In the particular case of the population screenings for local or regional diseases related to specific pathogens, the diagnosis of the presence of specific antibodies could drastically modify therapies and even the organization of public policies. The aim of this work was to develop a fast, cost-effective detection method based on the manipulation of functionalized magnetic beads for an efficient diagnosis of hypersensitivity pneumonitis (HP), looking for the presence of anti-pigeon antigen antibodies (APAA) in a patient’s serum. We presented a Diagnostic Biosensor Method (DBM) in detail, with validation by comparison with a traditional high-throughput platform (ELISA assay). We also demonstrated that it was compatible with a microfluidic chip that could be eventually incorporated into a PoC for easy and broad deployment using portable optical detectors. After standardization of the different reaction steps, we constructed and validated a plastic chip that could easily be scaled to high-volume manufacturing in the future. The solution proved comparable to conventional ELISA assays traditionally performed by the clinicians in their laboratory and should be compatible with other antibody detection directly from patient samples.

New detection method of SARS-CoV-2 antibodies toward a point-of-care biosensor

“…The SARS-CoV-2 AbDM is based on the one presented by Fiordelisio et al (2021), where magnetic beads functionalized with an antigen react with a serum sample (with an unknown concentration of primary antibodies to be detected) and subsequently with a fluorescent conjugated secondary antibody to detect the emitted signal.…”

“…For the plate detection reactions, incubation was performed at RT with shaking (250 rpm) for 2 h; finally, three washes were performed with B4 and resuspended in 50 µL of the same buffer. On the other hand, in the microfluidic chip, the incubation was 45 min at RT, with agitation by transverse magnet movement (TMM) (Fiordelisio et al, 2021). Subsequently, a wash was performed by transiting the beads through B4T and resuspending them in the same buffer for reading.…”

“…The SARS-CoV-2 AbDM was implemented on a microfluidic chip making use of an automated platform, both designed by Fiordelisio et al (2021). The chip consists of a series of six wells (I-VI) with different reagents connected by microchannels with mineral oil (M5904, Sigma-Aldrich, Steinheim, Germany) (Figure 1A) to prevent mixing of the different solutions.…”

“…The method, hereinafter called the SARS-CoV-2 antibody detection method (SARS-CoV-2 AbDM), employs a magnetic bead system that immobilizes the antigen (S protein or RBD) on its surface and allows determining the presence and quantity of both antibodies in a serum or whole blood sample in a single reaction. Our working group has already implemented this technology for the detection of hypersensitivity pneumonitis antibodies (Fiordelisio et al, 2021), where it was observed that the use of magnetic beads, due to their small size and spherical geometry, allows for maximizing the number of immobilized biomolecules and increasing the sensitivity of the immunoassays besides reducing the reaction times and volumes of solutions and antibodies.…”

A New Platform of Iron Oxide-Based Nanoparticles Assay Using GMR Chip-Based Sensor With Microcontroller

“…and transducers. Many efforts are being made to develop this method, both in terms of improving the MNPs surface functionalization [4], [5], [6] [7] and the transducer [3], [4], [8], [9], [10], [11].…”