Molecular films for sensors and molecular electronic networks

This paper confines itself to only two approaches, namely Langmuir-Blodgett (LB) technology and chemisorption both of which can take advantage of the self-assembling nature of certain molecular species. The authors discuss the techniques now available for depositing ordered molecular layers with specific reaction centres at the film surface. Chemical reactions at these centres may be followed by surface potential measurements and to a limited extent by FTIR. The stability of the films may be improved by polymerisation and in the case of the alkyne termination it is possible to form a conjugated network at the film surface. Attempts have been made to grow primitive molecular networks based on the strong affinity of avidin for biotin. Although molecular ordering is poor in LB deposited monolayers this technique is capable of being improved upon particularly if two-dimensional networks can be synthesised. The authors have shown also that tightly packed avidin/bisbiotin chains can be grown by chemisorption onto the surface of gold. It is feasible that similar techniques can be used to fabricate two- and ultimately three-dimensional networks