Photolinker-free photoimmobilization of antibodies onto cellulose for the preparation of immunoassay membranes

Abstract

International audiencePaper-based detection devices such as lateral flow immunoassays (LFIAs) are inexpensive, rapid, user-friendly and therefore highly promising for providing resource-limited settings with point-of-care diagnostics. Recently, this biosensing field has trended towards three-dimensional microfluidic devices and multiplexed assay platforms. However, many multiplexed paper-based biosensors implement methods incompatible with the conventional LFIA carrier material: nitrocellulose. It thus tends to be replaced by cellulose. This major material change implies to undertake a covalent immobilization of biomolecules onto cellulose which preserves their biological activity. In this perspective, the immobilization process elaborated in this study is entirely biocompatible. While antibody immobilization onto cellulose usually requires chemical modifications of either the biomolecule and/or the membrane, the light-based procedure presented here was performed without any chemical photolinker. Native biomolecules have been successfully immobilized onto paper sheets which therefore enable to perform LFIAs. More generally, the process expounded herein is fast, simple, cost-saving, environmentally-friendly and would be helpful to immobilize chemical-sensitive biomolecules onto cellulose sheets

Malaria and the ‘last’ parasite: how can technology help?

“…Figure 1 illustrates how unstructured the flow paths could be in a nitrocellulose membrane [ 36 ]. As the migration of liquid occurs in a porous network and is not actively controlled, a number of limitations arise: large volumes of sample needed, accumulation of reagents at the leading edge of the liquid flow, and increased cross-reactivity [ 37 ].…”

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Fig. 1 Scanning electron micrograph showing the porousity of nitrocellulose membrane (Reprinted with permission from [ 36 ] copyright 2014 Royal Society of Chemistry)

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Photo-assisted inkjet printing of antibodies onto cellulose for the eco2-friendly preparation of immunoassay membranes

“…According to previous optimization results, 41,44 the photoimmobilization process for antibody immobilization onto cellulose can be described as follows: (i) an antibody solution was dispensed onto a cellulose sheet (see previous section); (ii) antibodies were concentrated by drying of the impregnated paper at 37 C, in a ventilated oven, for 15 minutes; (iii) the system was irradiated at 365 nm (1050 mW cm À2 ) for 2 h 40 min (about 10 J cm À2 ) for inducing photoimmobilization; and (iv) papers were intensively rinsed with a washing buffer (0.1 M potassium phosphate buffer, pH 7.4, containing 0.5 M NaCl and 0.5% (v/v) Tween 20) for removing non-immobilized antibodies.…”

“…This process was therefore combined to the photolinker-free photograing procedure previously patented 41,44 in order to easily and rapidly localize antibodies onto cellulose sheets. This is the fastest and most easily undertaken process ensuring the localization of species onto a at support according to a well-dened and reproducible pattern.…”

“…Furthermore, this process combines inkjet printing of biomolecules with a photolinker-free photograing procedure previously patented [41][42][43][44] which ensures easy, rapid and strong immobilization of antibodies onto cellulose-based papers. Furthermore, this process combines inkjet printing of biomolecules with a photolinker-free photograing procedure previously patented [41][42][43][44] which ensures easy, rapid and strong immobilization of antibodies onto cellulose-based papers.…”