TY - JOUR A1 - Khalid, Waqas A1 - Göbel, Gero A1 - Hühn, Dominik A1 - Montenegro, Jose-Maria A1 - Rivera-Gil, Pilar A1 - Lisdat, Fred A1 - Parak, Wolfgang J. T1 - Light triggered detection of aminophenyl phosphate with a quantum dot based enzyme electrode TI - Journal of Nanobiotechnology N2 - An electrochemical sensor for p-aminophenyl phosphate (p APP) is reported. It is based on the electrochemical conversion of 4-aminophenol (4AP) at a quantum dot (QD) modified electrode under illumination. Without illumination no electron transfer and thus no oxidation of 4AP can occur. p APP as substrate is converted by the enzyme alkaline phosphatase (ALP) to generate 4AP as a product. The QDs are coupled via 1,4-benzenedithiol (BDT) linkage to the surface of a gold electrode and thus allow potential-controlled photocurrent generation. The photocurrent is modified by the enzyme reaction providing access to the substrate detection. In order to develop a photobioelectrochemical sensor the enzyme is immobilized on top of the photo-switchable layer of the QDs. Immobilization of ALP is required for the potential possibility of spatially resolved measurements. Geometries with immobilized ALP are compared versus having the ALP in solution. Data indicate that functional immobilization with layer-by-layer assembly is possible. Enzymatic activity of ALP and thus the photocurrent can be described by Michaelis- Menten kinetics. p APP is detected as proof of principle investigation within the range of 25 μM - 1 mM. Y1 - 2016 UR - https://opus4.kobv.de/opus4-th-wildau/frontdoor/index/index/docId/580 UR - https://nbn-resolving.org/urn:nbn:de:kobv:526-opus4-5808 SN - 1477-3155 VL - 9 IS - 46 ER -