Novel Homogeneous Anion Exchange Membranes for Reproducible and Sensitive Nucleic Acid Detection via Current-Voltage Characteristic Measurement.
One-pot synthesis of novel hydrogel-based anion exchange membranes (AEMs), with only a single-phase monomer mixture, was used to eliminate surface heterogeneity and generate reproducible electroconvective microvortices in the over-limiting region of the current-voltage characteristic (CVC) curves. Diallyldimethylammonium chloride (DDA) was used as the main component to provide the cation charge groups, and 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethyl acrylate (EGDMA) were used as the auxiliary structure monomers. The uniform membrane structure allowed reproducible and sensitive DNA detection and quantification, as probe-target surface complexes can gate the ion flux and produce large voltage shifts in the over-limiting region. Suppressed membrane curvature due to controlled swelling is a crucial part to avoid the reduction of depletion region for maintaining the influence of target gene hybridization. Fourier-transform infrared (FTIR) spectroscopy verified the synthesized membrane structure, with a residual vinyl group that allows easy carboxylation via additional photografting reaction. Consequently, a significantly higher DNA probe functionalization efficiency is obtained on the homogeneous AEMs, evidenced by the increasing nitrogen element content and bonding via X-ray photoelectron spectroscopy (XPS). The DDA content was optimized to provide a sufficient coulomb force between AEM and nucleic acid backbone to promote the specific binding efficiency but without high dimensional swelling which might change the surface geometry and restrict the voltage shifting for sensing in the over-limiting region, and the optimal DDA/HEMA ratio was found to be 4/10. The synthesized AEM sensor for recombinant 35S promoter sequence identification exhibited a reproducible calibration standard curve with dynamic range between 30 fM and 1 μM and high selectivity with only 0.01 V shift for 1 μM nontarget oligo.
['Chuang|Jie-Ning|JN|', 'Diao|Pei-Yin|PY|', 'Huang|Wen-Shan|WS|', 'Huang|Li-Fen|LF|', 'Senapati|Satyajyoti|S|', 'Chang|Hsueh-Chia|HC|', 'Sun|Yi-Ming|YM|http://orcid.org/0000-0002-7779-8714']
D000837:Anion Exchange Resins D015374:Biosensing Techniques D004247:DNA D015342:DNA Probes D018744:DNA, Plant D020100:Hydrogels D057230:Limit of Detection D008567:Membranes, Artificial D008689:Methacrylates D044085:Microfluidics D009693:Nucleic Acid Hybridization D030821:Plants, Genetically Modified D015203:Reproducibility of Results D013025:Soybeans D013499:Surface Properties
anion exchange membrane GMO biosensor current−voltage characteristic microfluidics