title: Paper strip whole cell biosensors: a portable test for the semiquantitative detection of bacterial quorum signaling molecules.
abstract: Herein, we report the development of a novel, inexpensive, and portable filter-paper-based strip biosensor for the detection of bacterial quorum sensing signaling molecules, N-acylhomoserine lactones (AHLs). AHLs are generally employed by Gram-negative bacteria for their cell-cell communication to control expression of specialized genes, such as those involved in biofilm formation and production of virulence factors, in a population-density-dependent manner. First, a bacterial cell-based sensing system employing components of AHL-mediated QS regulatory system as recognition elements and beta-galactosidase as the reporter protein was designed and developed. The bacterial-sensing cells were then liquid-dried on strips of filter paper. beta-Galactosidase as the reporter allows for the visual monitoring of the analyte-induced signal when a colorimetric method of detection is applied. The paper strip biosensor was able to detect low AHL concentrations down to 1 x 10(-8) M. Furthermore, it was successfully applied to the detection of AHLs in physiological samples, such as saliva. The filter-paper-based sensing strips could provide reproducible results upon storage at 4 degrees C for at least 3 months. In conclusion, a filter-paper-based strip biosensor was developed that allows for visual, fast, and convenient detection of AHLs in a dose-dependent manner in a test sample. In addition, it does not require expensive equipment or trained personnel and allows ease of transportation and storage. Therefore, we envision that this biosensor will serve as a simple and economical portable field kit for on-site monitoring of AHL in a variety of clinical and environmental samples.
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA.
authors.forename: Anjali
authors.initials: A
authors.lastname: Struss
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pasini
authors.forename: C Mark
authors.initials: CM
authors.lastname: Ensor
authors.forename: Nilesh
authors.initials: N
authors.lastname: Raut
authors.forename: Sylvia
authors.initials: S
authors.lastname: Daunert
mesh_terms: D001419:Bacteria / Q000166:cytology* / Q000235:genetics; D015374:Biosensing Techniques / Q000379:methods*; D002138:Calibration; D004926:Escherichia coli / Q000166:cytology / Q000235:genetics; D005818:Genetic Engineering; D006801:Humans; D007783:Lactones / Q000032:analysis* / Q000378:metabolism; D010209:Paper; D053038:Quorum Sensing; D011934:Reagent Strips; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry; D013997:Time Factors; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D007783:Lactones; D011934:Reagent Strips; D001616:beta-Galactosidase