Cellulose as a novel substrate for lateral flow assay

Bioactive paper is a product that includes functionalities based on selective reactions of biomolecules such as enzymes or antibodies. Lateral flow assay (LFA) tests are devices aimed at detecting the presence of a specific analyte in a sample liquid. The test sample flows along a membrane via capillary action. This article describes how a fibrous network should be modified in order to use paper as a membrane material in a lateral flow immunoassay (LFIA) test. Mass production methods of paper and its suitability for the rapid roll-to-roll manufacture of test strips create the possibility to significantly decrease the manufacturing costs of LFA membranes and to find new potential applications for LFA tests within paper and board products in which a LFA test could be integrated. Use of 80 g/m2 paper made of unbeaten, bleached eucalyptus pulp with a dosage of 2.5 g/kg PAE, as a membrane material for a non-competitive immunoassay test for hemoglobin was demonstrated. Furthermore, advantages of this paper in making microfluidic channels on paper and an idea to simplify manufacturing of LFA tests by utilising good mechanical properties of the paper membrane were also presented.