title: Screen-printed microsystems for the ultrasensitive electrochemical detection of alkaline phosphatase.
abstract: Screen printing technique has been used to manufacture a microsystem where the graphite-based electrodes hold both a functional and an architectural task. The thick film manufacturing technique has proved valid to develop a very low volume (ca. 20 microL) device where different electrochemical operations can be very efficiently performed. Biomolecule immobilisation within the microsystem for biosensors applications has been explored by inducing and optimizing the in situ generation of a potential pulse polypyrrole electropolymerised film entrapping either glucose oxidase or glucose dehydrogenase. This biomodified microsystem was applied to the ultrasensitive electrochemical detection of alkaline phosphatase yielding limits of detection below 10(-12) M for glucose oxidase and of 10(-15) M for glucose dehydrogenase modified systems, within 15 min of incubation time. The results obtained showed the advantages of using low volume microsystems in combination with an optimised polypyrrole-enzyme film, which displayed a good immobilisation efficiency in conjunction with a good diffusion of species through. Ultrasensitive detection of AP in combination with a stable and reproducible surface modification for entrapping of biomolecules opens the window for new electrochemical detection platform with great potential for integrated biosensor applications.
authors.affiliation: Bioengineering and Bioelectrochemistry Group, Dept. d'Enginyeria Química, Escola Tècnica Superior d'Enginyeria Química, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007, Tarragona, Spain.
authors.forename: Luz M
authors.initials: LM
authors.lastname: Santiago
authors.forename: Diego
authors.initials: D
authors.lastname: Bejarano-Nosas
authors.forename: Pablo
authors.initials: P
authors.lastname: Lozano-Sanchez
authors.forename: Ioanis
authors.initials: I
authors.lastname: Katakis
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis*; D015374:Biosensing Techniques; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D042843:Glucose 1-Dehydrogenase / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry; D013997:Time Factors
chemical_list: D004800:Enzymes, Immobilized; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D006108:Graphite; D042843:Glucose 1-Dehydrogenase; D005949:Glucose Oxidase; D000469:Alkaline Phosphatase