A sensitive DNA capacitive biosensor using interdigitated electrodes.
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-1to 105µL-1target 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.
School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA.
Lei
L
Wang
Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80523, USA.
Milena
M
Veselinovic
Department of Electrical & Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA.
Lang
L
Yang
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.
Brian J
BJ
Geiss
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.
David S
DS
Dandy
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.
Tom
T
Chen
D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D025802:Electric Capacitance; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D006046:Gold; D006801:Humans; D061925:Immobilized Nucleic Acids / Q000737:chemistry*; D057230:Limit of Detection; D009693:Nucleic Acid Hybridization; D019095:Point-of-Care Systems; D015203:Reproducibility of Results; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014901:West Nile Fever / Q000821:virology; D014902:West Nile virus / Q000737:chemistry
D015342:DNA Probes; D004277:DNA, Single-Stranded; D061925:Immobilized Nucleic Acids; D013438:Sulfhydryl Compounds; D006046:Gold; D004247:DNA
Affinity-based capacitive biosensor; Interdigitated electrodes; Nucleic acid-based biosensor; Pathogen detection; Point-of-care diagnostics; Viral diagnostics