High-throughput screening of transglutaminase activity using plasmonic fluorescent nanocomposites.

We describe a high-throughput screening (HTS) assay for transglutaminase (TG) enzyme activity using plasmonic fluorescent nanocomposites. We used TG to covalently crosslink 500 μM solution of 5'-biotinamidopentylamine (BP) to N,N'-dimethylcasein (DMC) which was adsorbed onto 384-well microplates. We then bound 0.

Rational redesign of glucose oxidase for improved catalytic function and stability.

Glucose oxidase (GOx) is an enzymatic workhorse used in the food and wine industries to combat microbial contamination, to produce wines with lowered alcohol content, as the recognition element in amperometric glucose sensors, and as an anodic catalyst in biofuel cells. It is naturally produced by several species of fungi, and genetic variants are known to differ considerably in both stability and activity. Two of the more widely studied glucose oxidases come from the species Aspergillus niger (A.

Multiplexed microneedle-based biosensor array for characterization of metabolic acidosis.

The development of a microneedle-based biosensor array for multiplexed in situ detection of exercise-induced metabolic acidosis, tumor microenvironment, and other variations in tissue chemistry is described. Simultaneous and selective amperometric detection of pH, glucose, and lactate over a range of physiologically relevant concentrations in complex media is demonstrated. Furthermore, materials modified with a cell-resistant (Lipidure(®)) coating were shown to inhibit macrophage adhesion; no signs of coating delamination were noted over a 48-h period.

A multifunctional thin film Au electrode surface formed by consecutive electrochemical reduction of aryl diazonium salts.

A multifunctional thin film surface capable of immobilizing two diverse molecules on a single gold electrode was prepared by consecutive electrodeposition of nitrophenyl and phenylboronic acid pinacol ester (PBA-PE) diazonium salts. Activation of the stacked film toward binding platinum nanoparticles (PtNPs) and yeast cells occurred via chemical deprotection of the pinacol ester followed by electroreduction of nitro to amino groups. FTIR spectral analysis was used to study and verify film composition at each stage of preparation.

Luminescent investigations of terbium(III) biosorption as a surrogate for heavy metals and radionuclides.

We describe a metal transport system for investigating the interfacial interactions between the anionic surface charge of a gram-negative bacterium (Escherichia coli) and a trivalent cationic metal, Tb3+. We believe this is the first description of the uptake kinetics, sub- and intracellular distribution, and temporal fate of Tb3+ ion in E. coli.

Electrically addressable diazonium-functionalized antibodies for multianalyte electrochemical sensor applications.

The direct electrically addressable deposition of diazonium-modified antibodies is examined for electrochemical immunosensing applications. The immobilized antibodies can be detected by the use of electroactive enzyme tags and nanoparticle-gold labeling. Control over antibody functionalization density and minimal spontaneous grafting of diazonium-antibody adducts is shown.

Diazonium-functionalized horseradish peroxidase immobilized via addressable electrodeposition: direct electron transfer and electrochemical detection.

A simple one-step procedure is introduced for the preparation of diazonium-enzyme adducts. The direct electrically addressable deposition of diazonium-modified enzymes is examined for electrochemical sensor applications. The deposition of diazonium-horseradish peroxidase leads to the direct electron transfer between the enzyme and electrode exhibiting a heterogeneous rate constant, ks, of 10.