Avidin–Biotin Technology in Gold Nanoparticle-Decorated Graphene Field Effect Transistors for Detection of Biotinylated Macromolecules with Ultrahigh Sensitivity and Specificity

Abstract

The strong and specific noncovalent interaction between avidin and biotin is widely exploited in different types of enzyme-linked immunosorbent assay kits, labeled immunosensors, and polymer-based sensing devices for the detection of different biomarkers specific to different diseases such as cancer and influenza. Here, we employed the avidin–biotin technology in a novel gold nanoparticle-decorated graphene field-effect transistor (AuNP-GFET) and demonstrated the specific detection of the biotinylated macromolecules such as biotinylated proteins and nucleotides in the sub-picomolar (pM) range. The AuNP-GFET was constructed by fabricating six pairs of interdigital electrodes on graphene transferred on a SiO2/Si substrate. The sensing performance of AuNP-GFET was characterized by the real-time two-terminal electrical current measurement upon injection of the analyte solution into a silicone pool preattached onto the electrodes. Avidin, a tetrameric biotin-binding protein with strong affinity and specificity, immobilized on AuNP-decorated single-layer graphene, was used as the sensing platform and transduced the electrical signal upon binding to the analyte macromolecules. The sensing capability of the AuNP-GFET was tested with the biotinylated protein A. Sensitivity of the present biosensor was estimated to be ∼0.4 pM. The specificity and applicability of the biosensor were confirmed using both synthetic and real samples. Because the biotin label can retain its binding capability to avidin with strong affinity and specificity even after conjugating with varieties of proteins and nucleotides, the present AuNP-GFET biosensor is expected to promote the research in developing different biosensors.

Rapid and Oriented Immobilization of Laccases on Electrodes via a Methionine-Rich Peptide

“…The method of immobilization has to be carefully selected to avoid denaturation of enzymes and loss of structural freedom required for their activity. Several methods have been applied for efficient enzyme immobilization on the electrode surface, such as avidin–biotin complexation, covalent bonding, entrapment, encapsulation, and cross-linking. − Besides, physical adsorption is another easiest and most straightforward method . It is reagent-free, cost-efficient, and generally non-destructive toward enzyme activity because it does not involve any functionalization.…”

Carbon-Dot-Enhanced Graphene Field-Effect Transistors for Ultrasensitive Detection of Exosomes

“…This explains the larger observed Dirac voltage shifts in CD-GFET in comparison to ND-FET sensors, assuming that both sensors have the same number of exosomes at their surfaces, due to lowering of its interfacial capacitance. Although there are some studies about deposited nanoparticles (NPs) like AuNPs an PtNPs on graphene to fabricate FET sensors, [52][53][54][55] these sensors do not fully exploit the capability of graphene sensors, rather than relying on the functionalization of NPs which makes the graphene surface largely unused. 52,53 This can impact the sensitivity and selectivity of the graphene sensor.…”

“…Although there are some studies about deposited nanoparticles (NPs) like AuNPs an PtNPs on graphene to fabricate FET sensors, − these sensors do not fully exploit the capability of graphene sensors, rather than relying on the functionalization of NPs which makes the graphene surface largely unused. , This can impact the sensitivity and selectivity of the graphene sensor. In contrast, we have demonstrated the functionalization of both graphene and CDs, resulting in a further increase of the sensitivity.…”

SARS-CoV-2 Tests: Bridging the Gap between Laboratory Sensors and Clinical Applications

“…A gold nanoparticle-decorated graphene field-effect transistor has been proposed for the detection of biotinylated macromolecules with ultrahigh sensitivity and specificity. 132 The authors employed an avidin–biotin technology to demonstrate the specific detection of biotinylated proteins and nucleotides in the sub-picomolar range. The graphene/Au nanoparticles were fabricated on a Si substrate.…”