Talanta 55 (2001) 1029–1038 Antibody-based immobilization of bioluminescent bacterial sensor cells J. Rajan Premkumar a , Ovadia Lev a, *, Robert S. Marks b , Boris Polyak b , Rachel Rosen a , Shimshon Belkin a a Diision of Enironmental Sciences, Fredy and Nadine Hermann Graduate School of Applied Science, The Hebrew Uniersity of Jerusalem, Jerusalem 91904, Israel b Department of Biotechnology Engineering, The Institute for Applied Biosciences, Ben -Gurion Uniersity of the Nege, PO Box 653, Beer -Shea 84105, Israel Received 4 May 2001; received in revised form 20 August 2001; accepted 20 August 2001 Abstract Whole-cell luminescent bioreporter sensors based on immobilized recombinant Escherichia coli are described and evaluated. The sensors were prepared by glutaraldehyde-anchoring of nonspecific anti-E. coli antibodies on aminosylilated gold or silica glass surfaces with subsequent attachment of the probe bacteria. We demonstrate the generality of the concept by attachment of several E. coli strains that express luciferase in response to different physiological stress conditions including heat shock, DNA damage (SOS), fatty acid availability, peroxide and oxidative stress. The sensors can be used either as single- or multiple-use disposable sensing elements or for continuous operation. We show compatibility with optical fiber technology. Storage stability of the sensors exceeded 5 months with no measurable deterioration of the signal. Repeatability on exposure in successive days was 15%, as was sensor to sensor reproducibility. Sensitivity and detection limits of the immobilized cells were comparable to that of non-immobilized bacteria. © 2001 Elsevier Science B.V. All rights reserved. Keywords: Bioluminescence; Sensor; E. coli ; Antibody www.elsevier.com/locate/talanta 1. Introduction Genetically modified reporter microorganisms can be used as sensitive and inexpensive analytical tools for laboratory and field toxicity assessment [1,2]. Such organisms can be ‘tailored’ to emit a readily detectable signal in response to pre-deter- mined environmental conditions. This is normally achieved by the selection of a gene induced in response to the desired stress, and the genetic fusion of its promoter to a gene or a group of genes coding for reporter proteins, the activity or presence of which can be easily monitored. In E. coli and other microorganisms, the use of colori- metric, electrochemical, fluorescent or luminescent whole-cell reporting has been successfully demon- strated [1,2]. In this paper, we make use of a set of * Corresponding author. Tel.: +972-2-6585558; fax: +972- 2-6586155. E-mail address: ovadia@vms.huji.ac.il (R.S. Marks). 0039-9140/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved. PII:S0039-9140(01)00533-1