A sensitive DNA capacitive biosensor using interdigitated electrodes

Lei Wang; Milena Veselinovic; Lang Yang; Brian J Geiss; David S Dandy; Tom Chen

doi:10.1016/j.bios.2016.09.006

A sensitive DNA capacitive biosensor using interdigitated electrodes

Biosens Bioelectron. 2017 Jan 15:87:646-653. doi: 10.1016/j.bios.2016.09.006. Epub 2016 Sep 2.

Authors

Lei Wang¹, Milena Veselinovic², Lang Yang³, Brian J Geiss⁴, David S Dandy⁵, Tom Chen⁶

Affiliations

¹ School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA.
² Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80523, USA.
³ Department of Electrical & Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA.
⁴ School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA; Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80523, USA.
⁵ School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA; Department of Chemical & Biological Engineering, Colorado State University, Fort Collins, CO 80523, USA.
⁶ School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA; Department of Electrical & Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA. Electronic address: chen@engr.colostate.edu.

Abstract

This paper presents a label-free affinity-based capacitive biosensor using interdigitated electrodes. Using an optimized process of DNA probe preparation to minimize the effect of contaminants in commercial thiolated DNA probe, the electrode surface was functionalized with the 24-nucleotide DNA probes based on the West Nile virus sequence (Kunjin strain). The biosensor has the ability to detect complementary DNA fragments with a detection limit down to 20 DNA target molecules (1.5aM range), making it suitable for a practical point-of-care (POC) platform for low target count clinical applications without the need for amplification. The reproducibility of the biosensor detection was improved with efficient covalent immobilization of purified single-stranded DNA probe oligomers on cleaned gold microelectrodes. In addition to the low detection limit, the biosensor showed a dynamic range of detection from 1µL^-1 to 10⁵µL^-1 target molecules (20 to 2 million targets), making it suitable for sample analysis in a typical clinical application environment. The binding results presented in this paper were validated using fluorescent oligomers.

Keywords: Affinity-based capacitive biosensor; Interdigitated electrodes; Nucleic acid-based biosensor; Pathogen detection; Point-of-care diagnostics; Viral diagnostics.

MeSH terms

Base Sequence
Biosensing Techniques / instrumentation
DNA / analysis*
DNA Probes / chemistry*
DNA, Single-Stranded / chemistry*
Electric Capacitance*
Electrochemical Techniques / instrumentation*
Electrodes
Equipment Design
Gold
Humans
Immobilized Nucleic Acids / chemistry*
Limit of Detection
Nucleic Acid Hybridization*
Point-of-Care Systems
Reproducibility of Results
Sulfhydryl Compounds / chemistry
West Nile Fever / virology
West Nile virus / chemistry

Substances

DNA Probes
DNA, Single-Stranded
Immobilized Nucleic Acids
Sulfhydryl Compounds
Gold
DNA

Grants and funding

R01 AI114675/AI/NIAID NIH HHS/United States