Microfluidic electrochemical glucose biosensor with in situ enzyme immobilization

Lokar, Nina (author), Pečar, Borut (author), Možek, Matej (author), Vrtačnik, Danilo (author)

The development and characterization of a microfluidic electrochemical glucose biosensor are presented herein. The transducer part is based on thin-film metal electrodes on a glass substrate. The biological recognition element of the biosensor is the pyrroloquinoline quinone–glucose dehydrogenase (PQQ-GdhB) enzyme, selectively in situ immobilized via microcontact printing of a mixed self-assembling monolayer (SAM) on a gold working electrode, while the microfluidic part of the device comprises microchannel and microfluidic connections formed in a polydimethylsiloxane (PDMS) elastomer. The electrode properties throughout all steps of biosensor construction and the biosensor response to glucose concentration and analyte flow rate were characterized by cyclic voltammetry and chronoamperometry. A measurement range of up to 10 mM in glucose concentration with a linear range up to 200 µM was determined. A detection limit of 30 µM in glucose concentration was obtained. Respective biosensor sensitivities of 0.79 nA/µM/mm$^2$ and 0.61 nA/µM/mm$^2$ were estimated with and without a flow at 20 µL/min. The developed approach of in situ enzyme immobilization can find a wide number of applications in the development of microfluidic biosensors, offering a path towards continuous and time-independent detection.

• Language: English
• Keywords: microfluidic glucose biosensor, electrochemical biosensor, thin film electrode, enzyme in situ immobilization, chronoamperometry, cyclic voltammetry
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 16 str.
• Numbering: Vol. 13, iss. 3, art. 364
• PID: 20.500.12556/RUL-154088
• UDC: 602.1:53.082.9
• ISSN on article: 2079-6374
• DOI: 10.3390/bios13030364
• COBISS.SI-ID: 145284355
• Publication date in RUL: 24.01.2024

Record is a part of a journal

• Title: Biosensors
• Shortened title: Biosensors
• Publisher: MDPI
• ISSN: 2079-6374
• COBISS.SI-ID: 523007769

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: mikrofluidni biosenzor glukoze, elektrokemični biosenzor, tankoplastna elektroda, imobilizacija encima in situ, kronoamperometrija, ciklična voltametrija

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0244
• Name: Mikrostrukture in nanostrukture

• Funder: ARRS - Slovenian Research Agency
• Project number: 1000-22-0510