Enhanced Rates of Electrolytic Styrene Epoxidation Catalyzed by Cross-Linked Myoglobin-Poly(l-lysine) Films in Bicontinuous Microemulsions

Abstract

Redox proteins attached to surfaces designed for biocatalysis hold promise for future clean synthetic routes. It is advantageous for these biocatalysts to operate in low-toxicity fluids with a high capacity to dissolve reactants. Here we report cross-linked films of myoglobin (Mb) and poly(L-lysine) (PLL) chemically attached to oxidized carbon cloth cathodes that in microemulsions feature the protein in a water-rich film environment with reactant in an oil-rich environment. These cross-linked Mb/PLL films were the most stable in microemuslions and had the largest turnover rates for epoxidation of styrene compared to lightly cross-linked or uncross-linked Mb/poly(styrene sulfonate) films. Up to 40-fold larger turnover rates were found in bicontinuous microemulsions compared to oil-in-water microemulsions and micelles. Enhanced turnover rates are correlated with up to 10-fold faster mass transport of solutes in the oil phases of the bicontinuous fluids.

Biocatalytic anode for glucose oxidation utilizing carbon nanotubes for direct electron transfer with glucose oxidase

“…The PLL-SWCNT/GOX assembly was made on basal plane pyrolytic carbon (PG) disk electrodes (A=0.16 cm 2 ) electrochemically oxidized as described previously [23]. PG was first covered with 10 μL freshly prepared 24 mM EDC and 10 μL 4 mM poly-L-lysine (PLL) to form amide linkages between electrode carboxylates and amino groups of PLL.…”

“…The goal of the present work was to construct a stable GOX anode that facilitates direct ET and evaluate its potential response to glucose concentration under aerobic conditions. For this, we utilized poly-L-lysine (PLL) covalently linked to pyrolytic graphite (PG), an approach developed previously without CNTs to stabilize enzymes [23–25] and with CNTs to stabilize antibodies [26]. …”

Improved Detection Limit and Stability of Amperometric Carbon Nanotube‐Based Immunosensors by Crosslinking Antibodies with Polylysine

“…2.3.1 (PLL-PAA)-Ab/Ag Assembly-PG electrodes were electrochemically oxidized as reported previously [19], then coated with 10 μL of 24 mM EDC and 10 μL of 4 mM PLL to form amide linkages between carboxylic groups on the electrode surface and amino groups of PLL. After 8 -12 hours, electrodes were rinsed with water and a 10 μL drop of 27 mM polyacrylic acid and 10 μL of 24 mM EDC was placed on the surface.…”

Electrochemical catalysis by crosslinked films of cobalt reconstituted myoglobin and poly(l-lysine) in a bicontinuous microemulsion

“…We investigated control of catalytic activity with microemulsion composition for adsorbed FeMb films [14]. More recently we made crosslinked films of FeMb-PLL that were stable in microemulsions and studied the factors important for efficient catalysis [15,16]. Given this background, we sought to combine the catalytic activity of the cobalt corrin surrounded by protein envelope with the reactivity control of microemulsions.…”