Open Access Nano Express

Nanostructured materials with biomimetic recognition abilities for chemical sensing

Sadia Zafar Bajwa1, Ghulam Mustafa1, Renata Samardzic1, Thipvaree Wangchareansak12 and Peter A Lieberzeit1*

Author affiliations

1 Department of Analytical Chemistry, University of Vienna, Währinger Strasse 38, Vienna, 1090, Austria

2 Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand

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Citation and License

Nanoscale Research Letters 2012, 7:328  doi:10.1186/1556-276X-7-328

Published: 21 June 2012

Abstract

Binding features found in biological systems can be implemented into man-made materials to design nanostructured artificial receptor matrices which are suitable, e.g., for chemical sensing applications. A range of different non-covalent interactions can be utilized based on the chemical properties of the respective analyte. One example is the formation of coordinative bonds between a polymerizable ligand (e.g., N-vinyl-2-pyrrolidone) and a metal ion (e.g., Cu(II)). Optimized molecularly imprinted sensor layers lead to selectivity factors of at least 2 compared to other bivalent ions. In the same way, H-bonds can be utilized for such sensing purposes, as shown in the case of Escherichia coli. The respective molecularly imprinted polymer leads to the selectivity factor of more than 5 between the W and B strains, respectively. Furthermore, nanoparticles with optimized Pearson hardness allow for designing sensors to detect organic thiols in air. The ‘harder’ MoS2 yields only about 40% of the signals towards octane thiol as compared to the ‘softer’ Cu2S. However, both materials strongly prefer molecules with -SH functionality over others, such as hydrocarbon chains. Finally, selectivity studies with wheat germ agglutinin (WGA) reveal that artificial receptors yield selectivities between WGA and bovine serum albumin that are only about a factor of 2 which is smaller than natural ligands.

Keywords:
Bivalent copper ions; Organic vapors; Wheat germ agglutinin lectin; Escherichia coli; Quartz crystal microbalance