Biosensing at disk microelectrode arrays. Inter-electrode functionalisation allows formatting into miniaturised...

Area of Science:

• Electrochemistry
• Biosensor technology
• Nanomaterials

Background:

• Biosensor specificity relies on effective transducer functionalization with biorecognition elements.
• Surface blocking steps are crucial for specificity but can hinder electron transfer in electrochemical biosensors.
• Conventional blocking methods may negatively impact the performance of amperometric biosensing systems.

Purpose of the Study:

• To develop improved amperometric biosensing platforms using microfabricated disk microelectrode arrays.
• To investigate a novel functionalization strategy focusing on the surface surrounding active microelectrodes.
• To enhance biosensor sensitivity and reduce detection limits for electrochemical detection.

Main Methods:

• Utilized microfabricated disk microelectrode arrays for biosensor development.
• Functionalized the inert surface surrounding active microdisks, deviating from conventional methods.
• Studied the electrochemical behavior of tetramethylbenzidine (TMB) as a redox mediator.
• Applied the TMB mediator for amperometric biosensing of horseradish peroxidase (HRP) and hydrogen peroxide (H2O2).

Main Results:

• The novel functionalization approach more than doubled assay sensitivity compared to conventional biosensors.
• Achieved highly sensitive detection of HRP down to 25 pM and H2O2 down to 0.54 pM.
• Demonstrated rapid detection within 5 seconds using only 10 microliters of sample.
• Observed enhanced rates of mass transport to microelectrodes, improving device sensitivity.

Conclusions:

• The developed method offers a promising strategy for creating faster and more sensitive electrochemical biosensing platforms.
• Functionalizing the surface around microelectrodes presents a significant advantage over traditional blocking techniques.
• Microelectrode arrays hold potential for advancing the field of electrochemical biosensing.