Direct writing of functional materials for milk point-of-care tests

Direct writing has been used in recent years as an emergent and potential fabrication method for the development of affordable point-of-care applications. This thesis focuses on the application of direct writing methods for milk point-of-care tests, specifically for the detection of residual antibiotics. Milk is one of the main products of the dairy industry, hence the presence of residues can cause several issues for human and animal health as well as economic problems associated with the dairy production. Lateral flow immunoassay (LFIA) and Surface Enhanced Raman Scattering (SERS) are the two techniques that have been exploited through pen direct writing of functional materials. In particular, a commercial fountain pen has been used for “handwriting” biomaterials or nanoinks on the nitrocellulose support or in a paper substrate. Thanks to the simplicity of the fabrication method, the versatility and do-it-yourself applicability, this approach allows to develop point-of-care tests without the need for expensive instrumentation, trained personnel and fully equipped laboratories. This in turn opens opportunities to test real-world applications in diverse fields and environments such as food safety, clinical diagnostics and environmental monitoring. The applicability of this approach has been validated through the detection of penicillin G residues in milk, using a dual detection LFIA coupled with SERS. A multiplex-LFIA for simultaneous detection of thiamphenicol and tylosin antibiotics has also been developed with a visual limit of detection of 100 ng/mL and the IC50 lower than the maximum residue limits set by the regulations in place. Finally, the direct writing approach has been employed in the fabrication of a label-free paper-based SERS sensor for detection of tetracycline residue in milk, opening the opportunities to analyze different contaminants in complex matrices.

Grantor dc:publisher

University College Cork

Year dc:date.issued

2025

Author dc:creator

• Russo, Alida

Advisors dc:contributor.advisor

• Iacopino, Daniela
• Lovera, Pierre

• Milk
• Antibiotics
• Direct writing
• Lateral flow immunoassay (LFIA)
• Surface Enhanced Raman Scattering (SERS)
• Nanoparticles

Statement dc:rights

• © 2025, Alida Russo.

Licence dc:rights.uri

• https://creativecommons.org/licenses/by-nc-sa/4.0/

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10468/17984

OAI identifier oai:identifier

oai:cora.ucc.ie:10468/17984