Multiplexed Readout of Enzymatic Reactions by Means of Laterally Resolved Illumination of Quantum Dot Electrodes.
ACS Appl Mater Interfaces
; 11(24): 21830-21839, 2019 Jun 19.
Article
en En
| MEDLINE
| ID: mdl-31117441
ABSTRACT
Triggering electrochemical reactions with light provides a powerful tool for the control of complex reaction schemes on photoactive electrodes. Here, we report on the light-directed, multiplexed detection of enzymatic substrates using a nonstructured gold electrode modified with CdSe/ZnS quantum dots (QDs) and two enzymes, glucose oxidase (GOx) and sarcosine oxidase (SOx). While QDs introduce visible-light sensitivity into the electrode architecture, GOx and SOx allow for a selective conversion of glucose and sarcosine, respectively. For the QD immobilization to the gold electrode, a linker-assisted approach using trans-4,4'-stilbenedithiol has been used, resulting in the generation of a photocurrent. Subsequently, GOx and SOx have been immobilized in spatially separated spots onto the QD electrode. For the local readout of the QD electrode, a new measurement setup has been developed by moving a laser pointer across the surface to defined positions on the chip surface. The amplitudes of the photocurrents upon illumination of the GOx or SOx spot depend in a concentration-dependent manner on the presence of glucose and sarcosine, respectively. This measurement also allows for a selective detection in the presence of other substances. The setup demonstrates the feasibility of multiplexed measurements of enzymatic reactions using a focused light pointer, resulting in an illumination area with a diameter of 0.3 mm for analyzing spots of different enzymes. Moving the laser pointer in the x- and y-direction and simultaneously detecting the local photocurrent also allow a spatial imaging of enzyme immobilization. Here, not only the spot dimensions but also the activity of the enzyme can be verified.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fotoquímica
/
Técnicas Biosensibles
/
Puntos Cuánticos
/
Electrodos
/
Técnicas Electroquímicas
Idioma:
En
Revista:
ACS Appl Mater Interfaces
Asunto de la revista:
BIOTECNOLOGIA
/
ENGENHARIA BIOMEDICA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Alemania