title: Plastic optical fiber-based biosensor platform for rapid cell detection.
abstract: This work presents a novel, fast response time, plastic optic fiber (POF) biosensor to detect Escherichia coli. It discloses the technique for the development, calibration and measurement of this robust and simple-to-construct POF biosensor. The probes in U-shaped format were manufactured with a specially developed device. The calibration process led to the evaluation of the sensitivity, accuracy and repeatability by using solutions of sucrose for obtaining refractive indices (RI) in the range 1.33-1.39 IR equivalent of water and bacteria, respectively. The POF probes were functionalized with antibody anti-E. coli serotype O55 and tested firstly with saline and then with bacterial concentrations of 10(4), 10(6), and 10(8) colony forming units/ml (CFU/ml). The optoelectronic setup consists of an 880 nm LED connected to the U-shaped probe driven by a sine waveform generated by the Simulink (from Matlab(®)). On the other side of the probe a photodetector generates a photocurrent which is amplified by a transconductance amplifier. The output voltage signal is read by the analog-to-digital (A/D) input of the microcontroller. In all tested concentrations, the results presented a tendency of a decrease in the output signal with time, due to the attachment of the bacteria to the POF probe and consequent increase in the RI close to the sensitive area of the fiber surface. It has been shown that the system is capable of providing positive response to the bacterial concentration in less than 10 min, demonstrating good possibilities to be commercially developed as a portable field sensor.
authors: Photonic and Instrumentation Laboratory, Electrical Engeineering Program, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil.
authors: Gisele
authors: G
authors: Wandermur
authors: Photonic and Instrumentation Laboratory, Electrical Engeineering Program, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil.
authors: Domingos
authors: D
authors: Rodrigues
authors: Division of Chemical, Biological and Nuclear Defence, Biological Defence Laboratory, Brazilian Army Technological Center, Rio de Janeiro, RJ, Brazil.
authors: Regina
authors: R
authors: Allil
authors: Photonic and Instrumentation Laboratory, Electrical Engeineering Program, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil.
authors: Vanessa
authors: V
authors: Queiroz
authors: Laboratory of Molecular Microbial Ecology, Department of General Microbiology, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil.
authors: Raquel
authors: R
authors: Peixoto
authors: Photonic and Instrumentation Laboratory, Electrical Engeineering Program, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil. Electronic address: werneck@lif.coppe.ufrj.br.
authors: Marcelo
authors: M
authors: Werneck
authors: Food Microbiology Laboratory, Department of Medical Microbiology, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil.
authors: Marco
authors: M
authors: Miguel
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D004926:Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000382:microbiology; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation; D055100:Optical Fibers; D010969:Plastics / Q000737:chemistry; D012680:Sensitivity and Specificity
chemical_list: D055910:Antibodies, Immobilized; D010969:Plastics
keywords: Biosensor; Cell detection; Immunosensor; Plastic optical fiber