Carbohydrate binding module-fused antibodies improve the performance of cellulose-based lateral flow immunoassays

Abstract

Since the pandemic outbreak of Covid-19 in December 2019, several lateral flow assay (LFA) devices were developed to enable the constant monitoring of regional and global infection processes. Additionally, innumerable lateral flow test devices are frequently used for determination of different clinical parameters, food safety, and environmental factors. Since common LFAs rely on non-biodegradable nitrocellulose membranes, we focused on their replacement by cellulose-composed, biodegradable papers. We report the development of cellulose paper-based lateral flow immunoassays using a carbohydrate-binding module-fused to detection antibodies. Studies regarding the protein binding capacity and potential protein wash-off effects on cellulose paper demonstrated a 2.7-fold protein binding capacity of CBM-fused antibody fragments compared to the sole antibody fragment. Furthermore, this strategy improved the spatial retention of CBM-fused detection antibodies to the test area, which resulted in an enhanced sensitivity and improved overall LFA-performance compared to the naked detection antibody. CBM-assisted antibodies were validated by implementation into two model lateral flow test devices (pregnancy detection and the detection of SARS-CoV-2 specific antibodies). The CBM-assisted pregnancy LFA demonstrated sensitive detection of human gonadotropin (hCG) in synthetic urine and the CBM-assisted Covid-19 antibody LFA was able to detect SARS-CoV-2 specific antibodies present in serum. Our findings pave the way to the more frequent use of cellulose-based papers instead of nitrocellulose in LFA devices and thus potentially improve the sustainability in the field of POC diagnostics.

Recent Progress on Rapid Lateral Flow Assay-Based Early Diagnosis of COVID-19

“…The result coincided with those of RT-PCR by testing the serum samples of COVID-19 patients and healthy individuals. Similar works have been reported by other laboratories ( Wen et al, 2020 ; Cavalera et al, 2021 ; Elter et al, 2021 ). Because the results of AuNP-based LFAs are mainly judged visually, the sensitivity is not sufficiently high and will inevitably lead to bias.…”

Ten Years of Lateral Flow Immunoassay Technique Applications: Trends, Challenges and Future Perspectives

“…Notwithstanding the exceptional properties of the nitrocellulose as solid support for the LFIA platform, researchers [ 291 , 292 , 293 ] are trying to replace its use with the cellulose that, in addition to further reducing costs, would have a reduced impact on the environment because its production process requires less chemicals in comparison to the nitrocellulose production. Most recently, promising results have been obtained by Adrian Elter et al that developed cellulose-based LFIAs [ 294 ]. However, their strategy consists in the use of carbohydrate binding module-fused antibodies and therefore it cannot be directly applied using currently available antibodies without additional steps.…”

Sustainable materials and COVID-19 detection biosensor: A brief review

“…Determination of Ig is an important diagnostic approach for diagnosis of SARS-Co-V2 infection. An example of new cellulose – based sensing system for Ig detection is a new LFA developed by Elter et al [ 32 ]. In the study by Elter et al, development of cellulose paper-based LFA was developed using a carbohydrate-binding module-fused approach [ 32 ].…”

“…An example of new cellulose – based sensing system for Ig detection is a new LFA developed by Elter et al [ 32 ]. In the study by Elter et al, development of cellulose paper-based LFA was developed using a carbohydrate-binding module-fused approach [ 32 ]. Graphene-Based Biosensors for COVID-19 detection …”