Optical Leaky Waveguide Sensor for Detection of Bacteria with Ultrasound Attractor Force

• Published in: Analytical chemistry (Washington) Vol. 77; no. 19; pp. 6163 - 6168
• Main Authors: Zourob, Mohammed, Hawkes, Jeremy J, Coakley, W. Terence, Treves Brown, Bernard J, Fielden, Peter R, McDonnell, Martin B, Goddard, Nicholas J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-10-2005
• Subjects: Analytical chemistry; Bacillus subtilis; Bacillus subtilis - ultrastructure; Bacteria; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Chemistry; Exact sciences and technology; General, instrumentation; Optics and Photonics; Spores, Bacterial; Ultrasonic technology; Performance evaluation; Antibody; Immobilization; Optical sensor; Metal; Chemical sensor; Waveguide; Optical system; Detection limit; Bacteria; Optical waveguide; Diffusion; Ultrasound
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac050605j

An integrated, sensitive, and rapid system was developed for the detection of bacteria. The system combined an optical metal-clad leaky waveguide (MCLW) sensor with ultrasound standing waves (USW). The performance of a MCLW sensor for the detection of bacteria has been increased (>100 fold) by using USWs to drive bacteria onto the sensor surface. By forming the USW nodes at or within the surface of the MCLW, the diffusion-limited capture rate has been replaced by fast movement. Immobilized anti-BG antibody on the MCLW sensor surface was used to capture Bacillus subtilis var. niger (BG) bacterial spores driven to the surface. This combination of sensor and attractor force combination has been tested by detecting the evanescent scattering from bacterial spores at the sensor surface. Application of ultrasound for 3 min gave a detection limit for BG bacterial spores of 1 × 103 spores/mL.