Cellulose immobilization strategies for paper-based immunoassays.

Paper-based analytical devices (PADs) enable the affordable, easy, rapid, and reliable detection of a range of analytes at the point-of-care. Cellulose is a versatile substrate for antibody attachment. However, how immunoreagents are immobilized onto cellulose plays an important role in assay performance. To provide an overview of the different antibody immobilization strategies used for developing PADs, we here critically review the existing literature from the last decade (2013–2023). First, we introduce cellulose as a substrate and summarize the different fabrication techniques for developing PADs. Thereafter, we delve into how antibodies are immobilized onto cellulose passively, covalently, or by affinity linkage. Affinity-based immobilization is further explored in a case study focused on using recombinant bifunctional proteins with cellulose-binding modules to anchor immunoreagents to cellulose. The final section discusses the validation and sustainable development of PADs addressing the existing and future challenges associated with developing such devices. [Display omitted] • Strategies for antibody immobilization onto cellulose substrates are reviewed. • Immobilizing antibodies in a site-selective manner improves analytical performance. • Cellulose requires modification before antibodies can be covalently attached to it. • Cellulose-binding modules facilitate antibody attachment onto unmodified cellulose. • Future challenges of developing sustainable paper-based immunoassays are discussed. [ABSTRACT FROM AUTHOR]