Highly tunable aptasensing microarrays with graphene oxide multilayers.

Area of Science:

• Biotechnology
• Materials Science
• Nanotechnology

Background:

• Graphene oxide (GO) is a promising material for biosensing applications.
• Layer-by-layer (LbL) assembly offers a method for creating tunable GO-based films.
• Fluorescence resonance energy transfer (FRET) is a mechanism used in biosensors for signal transduction.

Purpose of the Study:

• To develop a highly tunable LbL-assembled GO array for high-throughput multiplex protein sensing.
• To investigate the FRET-based mechanism for sensitive protein detection using aptamers.
• To evaluate the sensitivity and reusability of the developed GO biosensor.

Main Methods:

• Fabrication of a GO array using LbL assembly with varying bilayer numbers.
• Utilizing dye-labeled aptamers that exhibit FRET quenching with GO.
• Monitoring fluorescence recovery upon specific protein-aptamer binding for multiplex detection.
• Assessing the limit of detection for human thrombin and sensor reusability.

Main Results:

• Thin GO films (10 bilayers) demonstrated over 85% fluorescence quenching with dye-labeled aptamers.
• The GO array achieved highly sensitive detection of human thrombin, with limits of 0.1 nM (6 bilayers) and 0.001 nM (10 bilayers).
• The LbL assembly allowed for tunable sensitivity, and the GO chip was reusable up to four times.

Conclusions:

• The LbL-assembled GO array is a highly tunable and effective platform for high-throughput multiplex protein sensing.
• The FRET-based mechanism provides sensitive detection with tunable limits of detection.
• The developed biosensor demonstrates excellent reusability, making it a cost-effective solution for protein analysis.