Cellulose Nanofibers as a Module for Paper-Based Microfluidic Analytical Devices: Labile Substance Storage,...

Area of Science:

• Materials Science
• Analytical Chemistry
• Biotechnology

Background:

• Paper-based microfluidic analytical devices (μPADs) offer low-cost, portable diagnostics.
• Developing advanced materials for μPADs is crucial for expanding their capabilities.
• Cellulose-based materials are explored for their biocompatibility and structural properties.

Purpose of the Study:

• To investigate the potential of TEMPO-oxidized cellulose nanofibers (TOCN) as a functional module in μPADs.
• To demonstrate the ability of TOCN to stabilize biomolecules and control reaction kinetics.
• To develop semiquantitative μPADs for pesticide detection using TOCN.

Main Methods:

• Utilized TOCN as a matrix for immobilizing acetylcholinesterase (AChE) and indoxyl acetate (IDA).
• Investigated the storage stability of AChE and IDA within the TOCN matrix under dry conditions.
• Assessed the performance of TOCN-based μPADs in a biochemical reaction for indigo formation and pesticide detection.
• Explored the inkjet printability of TOCN dispersions due to their thixotropic properties.

Main Results:

• TOCN effectively stabilized unstable AChE and IDA during drying, releasing them upon rehydration.
• The TOCN network provided a reaction field with controlled kinetics, slower than solution-based reactions.
• Inkjet-printable TOCN dispersions facilitate scalable μPAD fabrication.
• Successfully constructed semiquantitative μPADs for detecting organic phosphorus pesticides.

Conclusions:

• TOCN is a promising material for enhancing the functionality and design flexibility of μPADs.
• TOCN-based μPADs offer a platform for developing portable, sensitive analytical devices.
• The integration of TOCN expands the universal applicability of paper-based analytical devices.