Protease Amperometric Sensor

• Published in: Analytical chemistry (Washington) Vol. 78; no. 18; pp. 6327 - 6331
• Main Authors: Ionescu, Rodica E., Cosnier, Serge, Marks, Robert S.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.09.2006
• Subjects: Analytical chemistry; Animals; Biochemistry, Molecular Biology; Bioengineering; Biological and medical sciences; Biomaterials; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Biotechnology; Cattle; Chemical Sciences; Chemistry; Disease; Ecotoxicology; Electrochemical methods; Electrochemistry - methods; Electrodes; Engineering Sciences; Environmental Engineering; Environmental Sciences; Exact sciences and technology; Food engineering; Fundamental and applied biological sciences. Psychology; Gelatin - chemistry; Gelatin - metabolism; Glucose Oxidase - chemistry; Glucose Oxidase - metabolism; Imaging; Life Sciences; Material chemistry; Materials; Medical diagnosis; Methods. Procedures. Technologies; Micro and nanotechnologies; Microelectronics; Molecular biology; Optics; or physical chemistry; Pancreas; Photonic; Platinum - chemistry; Polymers; Polymers - chemistry; Proteases; Pyrroles - chemistry; Quaternary Ammonium Compounds - chemistry; Swine; Theoretical and; Toxicology; Toxicology and food chain; Trypsin - analysis; Trypsin - metabolism; Various methods and equipments; Glucose oxidase; Hydrogen peroxide; Serine endopeptidases; Enzyme; Polymer; Digestion; Electrochemical detector; Peptidases; Trypsin; Response time; Platinum; Proteolysis; Biosensor; Amperometry; Hydrolases; Oxidoreductases
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac060253w

An amperometric biosensor for the detection of trypsin was developed. The latter was based on a two-layer configuration, namely, a polymer−glucose oxidase inner layer and a gelatin outer layer. In the presence of glucose, the enzyme layer produces H2O2 and hence an amperometric signal due to H2O2 electrooxidation was generated by potentiostating the electrode at 0.6 V. The biosensor detects the change in the increase in the maximum current caused by the proteolytic digestion of gelatin, which covers the platinum electrodes, thereby facilitating a speedier access for the glucose substrate to the electrode modified with both poly(pyrrole−alkylammonium) and glucose oxidase molecules. Our biosensor detected low trypsin concentrations down to 42 pM with a response time of ∼10 min, making it a very sensitive device in the detection of lower trypsin levels with such future putative applications as the diagnosis of pancreatic diseases.