tetano
Editor, Senior Moderator
Anal Chem. 2013 Nov 3. [Epub ahead of print]
Exploiting Enzyme Catalysis in Ultra-Low Ion Strength Media For Impedance Biosensing of Avian Influenza Virus Using a Bare Interdigitated Electrode.
Fu Y, Callaway Z, Lum J, Wang R, Lin J, Li Y.
Abstract
Enzymatic catalysis is broadly used in various fields but generally applied in media with high ion strength. Here we propose the exploitation of the enzymatic catalysis in ultra-low ion strength media to induce ion strength increase for developing a novel impedance biosensing method. Avian Influenza virus H5N1, a serious worldwide threat to poultry and human health, was adopted as the analyte. Magnetic beads were modified with H5N1-specific aptamer to capture the H5N1 virus. This was followed by binding Concanavalin A (ConA), Glucose oxidase (GOx), and Au nanoparticles (AuNPs) to create bionanocomposites through ConA-glycan interaction. The yielded sandwich complex was transferred to a glucose solution to trigger an enzymatic reaction to produce gluconic acid, which ionized to increase the ion strength of the solution, thus decreasing the impedance on a screen-printed interdigitated array electrode. This method took advantages of the high efficiency of enzymatic catalysis and the high susceptibility of electrochemical impedance on the ion strength, and endowed the biosensor with high sensitivity and a detection limit of 8 10-4 HAU in 200 L sample, which was magnitudes lower than that of some analogues based on biosensing methods. Furthermore, the proposed method required only a bare electrode for measurements of ion strength change and had negligible change on the surficial properties of the electrode, though some modification of magnetic beads/Au nanoparticles and the construction of a sandwich-complex were still needed. This helped to avoid the drawbacks of commonly used electrode-immobilization methods. The merit for this method makes it highly useful and promising for applications. The proposed method may create new possibilities in the broad and well-developed enzymatic catalysis fields and find applications in developing sensitive, rapid, low-cost, easy-to-operate biosensing and biocatalysis devices.
PMID:
24180352
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24180352
Exploiting Enzyme Catalysis in Ultra-Low Ion Strength Media For Impedance Biosensing of Avian Influenza Virus Using a Bare Interdigitated Electrode.
Fu Y, Callaway Z, Lum J, Wang R, Lin J, Li Y.
Abstract
Enzymatic catalysis is broadly used in various fields but generally applied in media with high ion strength. Here we propose the exploitation of the enzymatic catalysis in ultra-low ion strength media to induce ion strength increase for developing a novel impedance biosensing method. Avian Influenza virus H5N1, a serious worldwide threat to poultry and human health, was adopted as the analyte. Magnetic beads were modified with H5N1-specific aptamer to capture the H5N1 virus. This was followed by binding Concanavalin A (ConA), Glucose oxidase (GOx), and Au nanoparticles (AuNPs) to create bionanocomposites through ConA-glycan interaction. The yielded sandwich complex was transferred to a glucose solution to trigger an enzymatic reaction to produce gluconic acid, which ionized to increase the ion strength of the solution, thus decreasing the impedance on a screen-printed interdigitated array electrode. This method took advantages of the high efficiency of enzymatic catalysis and the high susceptibility of electrochemical impedance on the ion strength, and endowed the biosensor with high sensitivity and a detection limit of 8 10-4 HAU in 200 L sample, which was magnitudes lower than that of some analogues based on biosensing methods. Furthermore, the proposed method required only a bare electrode for measurements of ion strength change and had negligible change on the surficial properties of the electrode, though some modification of magnetic beads/Au nanoparticles and the construction of a sandwich-complex were still needed. This helped to avoid the drawbacks of commonly used electrode-immobilization methods. The merit for this method makes it highly useful and promising for applications. The proposed method may create new possibilities in the broad and well-developed enzymatic catalysis fields and find applications in developing sensitive, rapid, low-cost, easy-to-operate biosensing and biocatalysis devices.
PMID:
24180352
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24180352