An ion-exchange nanomembrane sensor for detection of nucleic acids using a surface charge inversion phenomenon

• Published in: Biosensors & bioelectronics Vol. 60; pp. 92 - 100
• Main Authors: Senapati, Satyajyoti, Slouka, Zdenek, Shah, Sunny S., Behura, Susanta K., Shi, Zonggao, Stack, M. Sharon, Severson, David W., Chang, Hsueh-Chia
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.10.2014; Elsevier
• Subjects: Base Sequence; Biological and medical sciences; Biosensing; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Charge inversion; Chromatography, Ion Exchange - instrumentation; Conductometry - instrumentation; DNA - analysis; DNA - chemistry; DNA - genetics; DNA Mutational Analysis - instrumentation; DNA/RNA; Electrokinetics; Equipment Design; Equipment Failure Analysis; Fundamental and applied biological sciences. Psychology; Membranes, Artificial; Methods. Procedures. Technologies; Molecular Sequence Data; Nanopores - ultrastructure; Nanoporous membrane; Nanotechnology - instrumentation; Nucleic Acids - analysis; Nucleic Acids - genetics; Reproducibility of Results; Sensitivity and Specificity; Sequence Analysis, DNA - instrumentation; Static Electricity; Various methods and equipments; DNA/RNA; Nanoporous membrane; Charge inversion; Biosensing; Electrokinetics; RNA; Detector; Biosensor; DNA; Membrane; Detection; Ion exchange; Nucleic acid; Nanoporosity
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2014.04.008

We present a novel low-cost biosensor for rapid, sensitive and selective detection of nucleic acids based on an ionic diode feature of an anion exchange nanoporous membrane under DC bias. The ionic diode feature is associated with external surface charge inversion on the positively charged anion exchange nanomembrane upon hybridization of negatively charged nucleic acid molecules to single-stranded oligoprobes functionalized on the membrane surface resulting in the formation of a cation selective monolayer. The resulting bipolar membrane causes a transition from electroconvection-controlled to water-splitting controlled ion conductance, with a large ion current signature that can be used to accurately quantify the hybridized nucleic acids. The platform is capable of distinguishing two base-pair mismatches in a 22-base pairing segment of microRNAs associated with oral cancer, as well as serotype-specific detection of dengue virus. We also show the sensor׳s capability to selectively capture target nucleic acids from a heterogeneous mixture. The limit of detection is 1pM for short 27 base target molecules in a 15-min assay. Similar hybridization results are shown for short DNA molecules as well as RNAs from Brucella and Escherichia coli. The versatility and simplicity of this low-cost biosensor should enable point-of-care diagnostics in food, medical and environmental safety markets. •An anion-exchange nanomembrane sensor for nucleic acid detection.•Detection mechanism based on surface charge inversion.•Detection of E. coli, dengue virus, Brucella, and microRNA associated with oral cancer.•We demonstrate a sensitivity down to 1pM concentration.•Sensor specificity shown using 2-base mismatch and heterogenous samples.