Graphene nanogap electrodes in electrical biosensing

Trupti Terse-Thakoor; Pankaj Ramnani; Claudia Villarreal; Dong Yan; Thien-Toan Tran; Tung Pham; Ashok Mulchandani

doi:10.1016/j.bios.2018.11.049

Graphene nanogap electrodes in electrical biosensing

Biosens Bioelectron. 2019 Feb 1:126:838-844. doi: 10.1016/j.bios.2018.11.049. Epub 2018 Dec 7.

Authors

Trupti Terse-Thakoor¹, Pankaj Ramnani², Claudia Villarreal³, Dong Yan⁴, Thien-Toan Tran⁵, Tung Pham², Ashok Mulchandani⁶

Affiliations

¹ Department of Bioengineering, University of California, Riverside, CA 92521, United States. Electronic address: tters001@ucr.edu.
² Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States.
³ Materials Science and Engineering Program, University of California, Riverside, CA 92521, United States.
⁴ Center for Nanoscale Science and Engineering (CNSE), University of California, Riverside, CA 92521, United States.
⁵ Department of Bioengineering, University of California, Riverside, CA 92521, United States; Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States.
⁶ Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, United States; Materials Science and Engineering Program, University of California, Riverside, CA 92521, United States. Electronic address: adani@engr.ucr.edu.

PMID: 30602266
DOI: 10.1016/j.bios.2018.11.049

Abstract

Graphene nanogap electrodes are reported here for the first time in an electrical biosensor for the detection of biomolecular interactions. Streptavidin-biotin was chosen as a model system for evaluating the sensor's performance. High-affinity interactions of streptavidin-gold nanoparticles (strep-AuNPs) to the biotin-functionalized nanogap localizes AuNPs, thereby bridging the gap and resulting in changes in device conductance. Biosensing performance was optimized by varying the gap size, AuNP diameter, and streptavidin coverage on AuNPs. The sensitivity and limit of detection (LOD) of streptavidin detection with the optimized parameters were determined to be 0.3 µA/nM and 0.25 pM, respectively. The proposed platform suggests high potential as a portable point-of-use biosensor for the detection of other affinity-based biomolecular interactions, such as antigen-antibody, nucleic acid, or chemo-selective interactions.

Keywords: Chemical vapor deposition; Electrical biosensor; Graphene; Nanogap electrode.

MeSH terms

Biosensing Techniques / instrumentation
Biosensing Techniques / methods*
Biotin / chemistry*
Electrochemical Techniques / methods*
Gold / chemistry
Graphite / chemistry*
Limit of Detection
Microelectrodes
Nanostructures / chemistry*
Nanotechnology
Particle Size
Streptavidin / chemistry*
Surface Properties

Substances

Biotin
Gold
Graphite
Streptavidin