Biosorption of Cu(II) and Pb(II) ions from aqueous solution by natural spider silk.

Aside from its excellent mechanical properties, spider silk (SS) would offer an active surface for heavy metal interaction due to its rich protein structure. The present study describes the potential use of natural (SS) as a sorbent of heavy metals from aqueous solutions. Single and multi-species biosorption experiments of heavy metals by natural SS were conducted using batch and column experiments.

Centri-voltammetric study with amberlite XAD-7 resin as a carrier system.

Centri-voltammetry is a novel method, which allows combining the advantages of centrifugation and voltammetry. The method offers a practical way for application of coprecipitation in trace analysis allowing direct voltammetric scan hence prevents the loss of the analyte, which usually is the case for other preconcentration techniques. The performance of the method was successfully tested using trace amounts of Pb(2+) ions in aqueous solution in a vessel specially designed to be compatible to both centrifugation and voltammetry.

Laccase biosensors based on mercury thin film electrode.

A biosensor was developed by immobilizing laccase onto mercury thin film electrode (MTFE) by means of gelatin that is then crosslinked with glutaraldehyde. Mercury thin film (MTF) was deposited onto glassy carbon electrode (GCE) and the obtained biosensor was utilized for the determination of phenolic compounds. The measurement was based on the amperometric detection of oxygen consumption in relation to analyte oxidation.

A novel amperometric biosensor based on artichoke (Cynara scolymus L.) tissue homogenate immobilized in gelatin for hydrogen peroxide detection.

A biosensor for specific determination of hydrogen peroxide was developed by using homogenized artichoke (Cynara scolymus L.) tissue in combination with a dissolved oxygen probe and applied in determination of hydrogen peroxide in milk samples. Artichoke tissue, which has catalase activity, was immobilized with gelatine by means of glutaraldehyde and fixed on a pretreated teflon membrane.