Love-wave bacteria-based sensor for the detection of heavy metal toxicity in liquid medium

• Published in: Biosensors & bioelectronics Vol. 26; no. 4; pp. 1723 - 1726
• Main Authors: Gammoudi, I., Tarbague, H., Othmane, A., Moynet, D., Rebière, D., Kalfat, R., Dejous, C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier B.V 15.12.2010; Elsevier
• Subjects: Acoustics; Bacteria; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensing Techniques - statistics & numerical data; Biosensor; Biosensors; Biotechnology; Cadmium - toxicity; Cells, Immobilized; Culture Media; Deposition; Dimethylpolysiloxanes; Electrolytes; Engineering Sciences; Escherichia coli; Escherichia coli - drug effects; Fundamental and applied biological sciences. Psychology; Heavy metals; Liquids; Love waves; Mercury - toxicity; Metals, Heavy - toxicity; Methods. Procedures. Technologies; Micro and nanotechnologies; Microelectronics; Multilayers; Polyamines; Polyelectrolyte; Polystyrenes; Real time; Self assembly; Sensors; Static Electricity; Various methods and equipments; Polyelectrolyte; Love waves; Biosensor; Escherichia coli; Heavy metals; Love wave; Toxicity; Liquid medium; Heavy metal; Detector; Bacteria; Detection; Enterobacteriaceae
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2010.07.118

The present work deals with the development of a Love-wave bacteria-based sensor platform for the detection of heavy metals in liquid medium. The acoustic delay-line is inserted in an oscillation loop in order to record the resonance frequency in real-time. A Polydimethylsiloxane (PDMS) chip with a liquid chamber is maintained by pressure above the acoustic wave propagation path. Bacteria ( Escherichia coli) were fixed as bioreceptors onto the sensitive surface of the sensor coated with a polyelectrolyte (PE) multilayer using a simple and efficient layer-by-layer (LbL) electrostatic self-assembly procedure. Poly(allylamine hydrochloride) (PAH cation) and poly(styrene sulfonate) (PSS anion) were alternatively deposited so that the strong attraction between oppositely charged polyelectrolytes resulted in the formation of a (PAH-PSS) n -PAH molecular multilayer. The real-time characterization of PE multilayer and bacteria deposition is based on the measurement of the resonance frequency perturbation due to mass loading during material deposition. Real-time response to various concentrations of cadmium (Cd 2+) and mercury (Hg 2+) has been investigated. A detection limit as low as 10 −12 mol/l has been achieved, above which the frequency increases gradually up to 10 −3 mol/l, after a delay of 60 s subsequent to their introduction onto bacterial cell-based biosensors. Beyond a 10 −3 mol/l a steep drop in frequency was observed. This response has been attributed to changes in viscoelastic properties, related to modifications in bacteria metabolism.