Fiber-optic luminescent sensors with composite oxygen-sensitive layers and anti-biofouling coatings.
Anti-biofouling polymers containing phosphorylcholine (PC)-substituted methacrylate units have been prepared by copolymerization with dodecyl methacrylate and used to coat luminescent oxygen sensors. Nanometer-sized coatings of such materials are shown to reduce significantly the adhesion of marine bacteria (more than 70%) and thrombocytes (more than 90%) to the surface of tris-(4,7-diphenyl-1,10-phenanthroline)ruthenium(II)-doped silicone layers. A thorough analytical characterization of both the PC-coated and the uncoated dyed films has demonstrated that the anti-biofouling layers do not alter dramatically the performance of the fiber-optic oxygen sensors in aqueous media and are mechanically stable for more than one year of continuous immersion. The slope of the linear calibration plots in the 0-8 mg L(-1) oxygen concentration range (ca. 1.0 L mg(-1)) decreases 8-11% after applying the 50-nm protective layer with no change in the sensor precision (1.1-1.9% RSD, n = 6). The response time of the 200-microm O2-sensitive layers (1.5-6 min) increases up to 2-fold, depending on the nature of the PC polymer used, but the temperature effect on the sensor response (0.020 L mg(-1) degrees C(-1)) remains essentially unchanged. Oxygen detection limits as low as 0.04 mg L(-1) have been measured with the coated optodes. The novel biofouling-resistant optosensors have been successfully validated against a commercial oxygen electrode and are shown to respond faster than the electrochemical device for large oxygen concentration changes. The biomimetic coatings will be particularly useful for drift-free long-term operation of environmental optosensors and in vivo fiber-optic oxygen analyzers.
Navarro
F
F
Department of Organic Chemistry, Universidad Complutense de Madrid, Spain.
Villoslada
Orellana
G
G
Moreno-Bondi
M C
MC
Vick
T
T
Driver
M
M
Hildebrand
G
G
Liefeith
K
K
D001422:Bacterial Adhesion; D001672:Biocompatible Materials / Q000032:analysis; D019149:Bioreactors / Q000382:microbiology; D015374:Biosensing Techniques / Q000295:instrumentation*; D001792:Blood Platelets / Q000737:chemistry / Q000502:physiology; D004867:Equipment Design; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006801:Humans; D008163:Luminescent Measurements; D055100:Optical Fibers; D010100:Oxygen / Q000032:analysis*; D010767:Phosphorylcholine / Q000032:analysis; D011108:Polymers / Q000378:metabolism; D013499:Surface Properties
D001672:Biocompatible Materials; D011108:Polymers; D010767:Phosphorylcholine; D010100:Oxygen