Nanomaterial could revolutionise molecular sensing

Researchers from Monash University and the University of Sydney have designed a material containing holes one millionth of a millimetre wide that could provide a new mechanism for sensing molecules.

The nanomaterial has a structure similar to chicken wire and is made up of a framework of iron atoms linked by molecular bridges. The material's framework contains nano-sized channels that are porous and can absorb 'guest' molecules that can cause the material to change colour.

Dr Cameron Kepert, from the University of Sydney's School of Chemistry, said the material was unique in being the first porous material to contain molecular switching sites. "These sites, known as spin crossover centres, can switch between two different colours and geometries in the presence of certain molecules," Dr Kepert said. The new class of materials to emerge from this work could have applications in the field of molecular sensing because the switching sites are able to sense the presence of guest molecules.

Dr Kepert and PhD student Greg Halder from the University of Sydney designed the material and identified its porous properties. They collaborated with Professor Keith Murray and others from Monash University to characterise the electronic switching properties of the material.

Professor Murray said that the new materials could be designed to selectively sense specific types of molecules through careful control of the switching sites. Dr Kepert added that controlling the size and shape of the holes would further enhance this selectivity.

They believe that the sensing capability of the materials could have possible environmental, medical and technological applications. Potential uses include detecting polluting molecules in the environment or alcohol on the breath of drivers.

Item provided courtesy of Monash University