A Novel Fiber Optic Biosensor for the Determination of Adrenaline Based on Immobilized Laccase Catalysis

Abstract

A novel fiber optic biosensor for the determination of adrenaline based on immobilized laccase catalysis and fluorescence quenching was designed and fabricated. The immobilized laccase formed by the immobilization of laccase on the CuTAPc-Fe₃O₄ nanoparticles composite were used to catalyze the oxidation of adrenaline and the fluorescent oxygen-sensing membrane was used to detect the consumption of oxygen. The effects of pH and temperature on laccase activity using adrenaline as the substrate were studied. The optimal pH and temperature for the activity of immobilized laccase are 5.0 and 55°C, respectively. The immobilized laccase has good thermal, storage and operation stability. The lock-in technology was used to detect the change of the life time of the oxygen-sensing membrane. By using ABTS as the electron mediator, the biosensor showed a response time of 30 sec. The biosensor has good performance in the adrenaline concentration ranges of 2.0 × 10⁻⁷ to 9.0 × 10⁻⁷ mol/l and 1.0 × 10⁻⁸ to 9.0 × 10⁻⁸ mol/l, and it also shows good stability.

Keywords:

• Adrenaline
• Fiber optic biosensor
• Immobilized laccase

The authors wish to acknowledge the following financial supports: The National Natural Science Foundation of China (Project No. 60377032) and Key Project (No. 60537050); the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT, No. IRT0547) and the Ministry of Education, China.

Additional information

Notes on contributors

Jun Huang

Jun Huang graduated from Wuhan University, China, in 1982 .Dr Huang completed his PhD from Wuhan University of Technology, China, in 1999. He is now a full professor of Wuhan University of Technology. His research interests focus primarily on fiber optical sensing materials, fiber optic chemical and biological sensors, and nanocomposite materials.

Hua Fang

Hua Fang received her M.S. degree from Hubei University, China, in 1999. She is currently pursuing the PhD degrees in Wuhan University of Technology, China, in the field of biomaterials and biosensors.

Cheng Liu

Cheng Liu is a postgraduate student of Wuhan University of Technology. He is engaged in the research of fiber optical biological sensors.

Erdan Gu

Erdan Gu obtained his PhD degree form University of Aberdeen, UK, in 1992. His research interests include thin film physics, thin film growth, device fabrication and characterization, photonics and sensor device applications.

Desheng Jiang

Desheng Jiang graduated from Wuhan University of Technology, China, in 1975. He is now the chief professor of Wuhan University of Technology. His research interests focus primarily on optical sensing materials and devices, fiber optic sensors and systems, and materials processing.