Artificial membranes can reveal biological weapons

Today there is a great need for portable equipment that can quickly detect chemical and biological weapons such as nerve gases, viruses, bacteria, and toxins. In a new dissertation the Swedish researcher Inga Gustafsson shows that artificial membranes can be used for this purpose in future biosensors.

Biosensors have already proven to be useful in the detection of impurities in food and water, for example. They have also been used in industrial processes, clinical analyses, and the development of pharmaceuticals.

In her dissertation, Inga Gustafsson, Department of Chemistry, Umeå University, and FOI, the Swedish Defence Research Agency , studies artificial membranes in biosensors.

Many hazardous substances bind to receptors in cell membranes at some stage. By using artificial membranes with specific binding sites it has been shown that these membranes can be used in future biosensors for detecting hazardous substances.

Inga Gustafsson’s study has helped identify factors that can affect the construction of model membranes on solid surfaces. These have proven to be of use in studying reactions occurring on the cell membrane. With further development they can be suitable for use as sensor surfaces in biosensors.

The membranes have been characterized and tested using various techniques. The experiments could be repeated with good stability. Membrane proteins have been built into the membranes and analyzed in regard to retained activity. The proteins introduced were bacteriorhodopsin, cytochrome oxidase, acetylcholine esterase, and the nicotine-like acetylcholine receptor.

The investigation revealed that the proteins were individually distributed in the membrane and that they retained their activity. Certain proteins were active for several weeks. Various glycolipids that can act as receptors for bacteria, viruses, and toxins were also introduced in the artificial membranes. The binding of the toxin ricin to these receptors was studied. The binding of the toxin to the membrane with glycolipids varied depending on pH, charge, and length of the sugar segment of the sugar lipid.