Development of a paper-based lateral flow immunoassay for simultaneous detection of lipopolysaccharides of Salmonella serovars

Abstract

Lateral flow type detection is becoming interesting not only in regions with a poor medical infrastructure but also for practitioners in day-to-day clinical work or for veterinary control in case of possible epidemics. In this work, we describe the first steps of development of a multi-channel strip with potential internal calibration of multiparametric and colorimetric lateral flow assays for the simultaneous detection of the lipopolysaccharides (LPS) of Salmonella typhimurium (S. typhimurium) and Salmonella enteritidis (S. enteritidis). We structured four channels in the nitrocellulose membrane with a Yb:KGW solid-state femtosecond laser ("cold" ablation process) to form distinct tracks of porous material and used gold nanoparticles for the labeling of the antibodies. In addition, calibration curves of the spot intensities of both serovars are presented, and it was shown that no cross reactivity between the different capture antibodies and LPS occurred. Finally, we detected LPS of both Salmonella serovars simultaneously. The color changes (spot intensities of the reaction zones) were evaluated using the open-source image-processing program ImageJ. Graphical abstract Multiparametric testing, strip A was tested with LPS S. enteritidis ( c=0.01 g/L) and LPS S.typhimurium ( c=0.0001 g/L), strip B with LPS S. enteritidis ( c=0.001 g/L) and LPS S. typhimurium ( c=0.001g/L) and strip C with LPS S. enteritidis (c=0.0001 g/L) and LPS S. typhimurium ( c=0.01 g/L), and read-out.

ABC Spotlight on paper-based strips analytics

“…Such paper-based assays are nowadays even used in the genotyping of single nucleotide polymorphism, where the digital camera can be replaced with a smartphone as a detector [10]. New approaches have a structure that allows multichannel devices that make possible multianalyte detection or internal referencing [11]. The nitrocellulose strips are structured into a fluidic network by short laser pulses.…”

Development of a Lateral Flow Highway: Ultra-Rapid Multitracking Immunosensor for Cardiac Markers

“…As a result, during the movement of the liquid front, the majority of conjugates passed outside the binding zone and were, therefore, lost. Furthermore, the previously described integration of the parallel flows of reagents of different specificities was accomplished with a significant increase in the complexity of the test strip, through additional modifications of the working membrane or the inclusion of additional components in the test strip [17][18][19][20].…”

Lateral Flow Assay for Salmonella Detection and Potential Reagents

“…These pairs are most readily available for relatively common and high-volume assays, such as tests for pregnancy, infectious disease, cardiac markers, and malignancies. Abs specific to various antigens of Salmonella species are in use for the development of LFAs [27,[29][30][31]. The common Ab-based LFAs for Salmonella recognition require these steps: (i) coating of GNPs with target specific Abs (detection Abs) via chemical or physical adsorption under the optimal pH value, (ii) immobilization of capture Abs on nitrocellulose membrane, and (iii) preparation of the pad and running buffers which has the optimal releasing effect through the membrane.…”