Jung, J. Lakatos, Mathias Bengs, S. Matys, S. Raff, J. Blüher, A. Cuniberti, G. 2019-11-01 Bacterial surface layer proteins (S-layer) possess unique binding properties for metal ions. By combining the binding capability of S-layer proteins with the optical properties of gold nanoparticles (AuNP), namely plasmonic resonance, a colorimetric detection system for metal and metalloid ions in water was developed. Eight S-layer proteins from different bacteria species were used for the functionalization of AuNP. The thus developed biohybrid systems, AuNP functionalized with S-layer proteins, were tested with different metal salt solutions, e.g. Indium(III)-chloride, Yttrium(III)-chloride or Nickel(II)-chloride, to determine their selective and sensitive binding to ionic analytes. All tested S-layer proteins displayed unique binding affinities for the different metal ions. For each S-layer and metal ion combination markedly different reaction patterns and differences in concentration range and absorption spectra were detected by UV/vis spectroscopy. In this way, the selective detection of tested metal ions was achieved by differentiated analysis of a colorimetric screening assay of these biohybrid systems. A highly selective and sensitive detection of yttrium ions down to a concentration of 1.67 × 10−5 mol/l was achieved with S-layer protein SslA functionalized AuNP. The presented biohybrid systems can thus be used as a sensitive and fast sensor system for metal and metalloid ions in aqueous systems. application/pdf https://folia.unifr.ch/global/documents/308130 https://folia.unifr.ch/documents/308130/files/lak_slp.pdf https://folia.unifr.ch/documents/308130/files/lak_slp_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.colsurfb.2019.06.014 info:eu-repo/semantics/openAccess License undefined Colloids and Surfaces B: Biointerfaces. - 2019, vol. 183, p. 110284 info:eu-repo/classification/udc/53 S-layer protein-AuNP systems for the colorimetric detection of metal and metalloid ions in water http://purl.org/coar/resource_type/c_6501