Thin multicomponent films for functional enzyme devices and bioreactor particles

Abstract

Complex functional films containing enzymes and other biomolecules are easily fabricated in nm-scale thicknesses by using layer-by-layer (LbL) methodologies first popularized by Lvov and Decher. In this review, we highlight the high level functional capabilities possible with LbL films of biomolecules based on our own research experiences. We first describe the basics of enzyme film fabrication by LbL alternate electrostatic adsorption, then discuss how to make functional enzyme-polyion films of remarkably high stability. Focusing on cytochrome P450s, we discuss films developed to electrochemically activate the natural catalytic cycle of these key metabolic enzymes. We then describe multifunctional, multicomponent DNA/enzyme/polyion films on arrays and particle surfaces for high throughput metabolic toxicity screening using electrochemiluminescence and LC-MS/MS. Using multicomponent LbL films, complex functionality for bioanalytical and biochemical purposes can be achieved that is difficult or impossible using conventional approaches.

Layer-by-Layer Assembly of Carbon Nanotubes Modified with Invertase/Glucose Dehydrogenase Cascade for Sucrose/O2Biofuel Cell

“…Till date, several reports have been published on various approaches to assemble enzymes on the anodes in BFCs utilizing carbon based materials. [1][2][3][4] Amongst those layerby-layer (LbL) assembly technique via electrostatic interactions of oppositely charged species has emerged as a very attractive way to construct multilayer films of polyelectrolytes, biomolecules, 5 and organic materials [6][7][8] offering advantages in various fields, such as surface functionalization, 9,10 drug delivery, 11,12 and biosensing. [13][14][15] Its application was considered plausible in the development of amperometric biosensors initiating vast research activities on biosensors comprised of LbL organized multilayers.…”

Effects of geometrical confinement in membrane pores on enzyme-based layer-by-layer assemblies

“…The investigation of enzymes by CD on solid surfaces is scarce in the literature [53]. Up to now, monitoring of structural changes after the adsorption A c c e p t e d M a n u s c r i p t onto solid surfaces is done by comparison of the spectra of free and immobilized peptides and proteins [17,54,55]. The similarity of both spectra is relevant, yet the best way to evaluate the correlation between a native and an immobilized protein structure is to calculate the secondary structure fractions (of -helix and -sheet) using standard algorithms [53].…”

“…In addition, the polyionic character of opposite charge could help to preserve the secondary structure when facing denaturating agents [4,15]. Enzymes in LbL films can increase their life-time and stability [16,17], which makes LbL an interesting option for biomedical applications such as enzyme prodrug therapy [16,18]. Since LbL has no restriction with respect to adsorbing substrate size and topology [19], protein multilayer films have been deposited on planar substrates, colloidal particles and membranes [4,20].…”

Modern approaches to chemical toxicity screening

“…5,38,39 Damaged DNA disorders the double helix of DNA to provide better access of Ru III sites in the polymer to reactive guanines in DNA, providing larger current signals than for intact DNA. 5,40 For LC-MS/MS, similar films without RuPVP are grown on magnetic beads. Metabolic enzyme reactions are performed in 96 well filter plates, and hydrolyzed DNA containing damaged nucleobases is collected by filtration into another plate for LC-MS/MS.…”