In situ modification of lipid-loaded MCM-41 channels with bovine serum albumin at a planar lipid bilayer for biosensing

Abstract

An in situ method for modifying a receptor site on mesoporous silica MCM-41 channels in planar lipid bilayers is described, in which bovine serum albumin (BSA) is covalently linked to the MCM-41 channels via head groups of lipids loaded in the nanopores. Prior to receptor modification, lipid-loaded MCM-41 channels were incorporated with lipid bilayers formed at an aperture of a Teflon film. The in situ coupling of BSA to lipid-loaded MCM-41 channels at the lipid bilayer interface was achieved by the sulfhydryl coupling method. The lipid bilayers containing BSA-modified MCM-41 exhibited channel-like currents, which were augmented in a concentration-dependent manner by the addition of anti-BSA at fM level. The in situ modification of lipid-loaded MCM-41 channels with BSA by the amine coupling technique was also investigated. The potential of the present approach for the development of channel-type biosensors is discussed in terms of modifying bilayer interfaces with bioreceptors.