Supported ionic liquids as customizable materials to purify immunoglobulin G

•Novel silica supports modified with ionic liquids were developed.•Customized supported ionic liquid materials were designed for IgG purification.•Factorial design was used to optimise the experimental conditions of IgG purification.•IgG can be recovered in aqueous solution or on the material’s surface.•IgG structure and activity are preserved during purification.