Method for the fabrication of a fluid flow regulating pad for a lateral flow immunoassay and corresponding lateral flow immunoassay

A method for the fabrication of a lateral flow test device intended to detect the presence of at least one predefined chemical, biological or biochemical entity in a sample, comprising the steps consisting in providing, following the flow direction of the sample on the test device:

• a sample pad,
• a conjugate pad intended to include at least one free labelled entity, which is optically or magnetically detectable and is adapted to react exclusively with said at least one predefined chemical, biological or biochemical entity so as to create a combined entity, and
• a working membrane including at least one test line intended to bear:
• either a first type detection entity adapted to react exclusively with said combined entity in order to immobilize said combined entity on said working membrane,
• or a second type detection entity adapted to react exclusively with said at least one free labelled entity in order to immobilize said at least one free labelled entity on said working membrane,
• the method comprising a further step of integrating a fluid flow regulating pad in the lateral flow test device, wherein said fluid flow regulating pad includes a nanocellulose aerogel pad manufactured by implementing steps consisting in:
• a) providing a hydrogel containing nanocellulose fibers,
• b) conducting a chemical crosslinking of said nanocellulose fibers,
• c) conducting a lyophilisation of the hydrogel containing the crosslinked nanocellulose fibers so as to define a nanocellulose aerogel, and
• d) compacting and shaping a predefined amount of said nanocellulose aerogel so as to define said nanocellulose aerogel pad.

A lateral flow test device intended to detect the presence of at least one predefined chemical, biological or biochemical entity in a sample, comprising, following the flow direction of the sample on the test device,

• a sample pad,
• a conjugate pad intended to include at least one free labelled entity, which is optically or magnetically detectable and is adapted to react exclusively with said at least one predefined chemical, biological or biochemical entity so as to create a combined entity, and
• a working membrane including at least one test line intended to bear:
• either a first type detection entity adapted to react exclusively with said combined entity in order to immobilize said combined entity on said working membrane,
• or a second type detection entity adapted to react exclusively with said at least one free labelled entity in order to immobilize said at least one free labelled entity on said working membrane,
• the test device further including a nanocellulose aerogel pad made of a compacted aerogel containing crosslinked nanocellulose fibers.