title: Amperometric L-lactate biosensor based on screen-printed carbon electrode containing cobalt phthalocyanine, coated with lactate oxidase-mesoporous silica conjugate layer.
abstract: A novel amperometric biosensor for the measurement of L-lactate has been developed. The device comprises a screen-printed carbon electrode containing cobalt phthalocyanine (CoPC-SPCE), coated with lactate oxidase (LOD) that is immobilized in mesoporous silica (FSM8.0) using a polymer matrix of denatured polyvinyl alcohol; a Nafion layer on the electrode surface acts as a barrier to interferents. The sampling unit attached to the SPCE requires only a small sample volume of 100 μL for each measurement. The measurement of l-lactate is based on the signal produced by hydrogen peroxide, the product of the enzymatic reaction. The behavior of the biosensor, LOD-FSM8.0/Naf/CoPC-SPCE, was examined in terms of pH, applied potential, sensitivity and operational range, selectivity, and storage stability. The sensor showed an optimum response at a pH of 7.4 and an applied potential of +450 mV. The determination range and the response time for L-lactate were 18.3 μM to 1.5 mM and approximately 90s, respectively. In addition, the sensor exhibited high selectivity for L-lactate and was quite stable in storage, showing no noticeable change in its initial response after being stored for over 9 months. These results indicate that our method provides a simple, cost-effective, high-performance biosensor for l-lactate.
authors.affiliation: Funai Electric Advanced Applied Technology Research Institute Inc. (FEAT), Sengen, Tsukuba-shi, Ibaraki, Japan. shimomura.t@funai-atri.co.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimomura
authors.forename: Touru
authors.initials: T
authors.lastname: Sumiya
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ono
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Ito
authors.forename: Taka-aki
authors.initials: TA
authors.lastname: Hanaoka
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000737:chemistry*; D019344:Lactic Acid / Q000032:analysis*; D006899:Mixed Function Oxygenases / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D007211:Indoles; D009942:Organometallic Compounds; C063633:cobalt phthalocyanine; D019344:Lactic Acid; D002244:Carbon; D012822:Silicon Dioxide; D011142:Polyvinyl Alcohol; D006861:Hydrogen Peroxide; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase