@article{WeldenJablonskiWegeetal.2021,
  author    = {Welden, Rene and Jablonski, Melanie and Wege, Christina and Keusgen, Michael and Wagner, Patrick Hermann and Wagner, Torsten and Sch{\"o}ning, Michael Josef},
  title     = {Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase},
  series = {Biosensors},
  volume    = {11},
  journal   = {Biosensors},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-6374},
  doi       = {10.3390/bios11060171},
  pages     = {Artikel 171},
  year      = {2021},
  abstract  = {The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte's pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS.},
  language  = {en}
}
@article{MiyamotoSatoAbeetal.2016,
  author    = {Miyamoto, Ko-Ichiro and Sato, Takuya and Abe, Minami and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Light-addressable potentiometric sensor as a sensing element in plug-based microfluidic devices},
  series = {Micromachines},
  volume    = {7},
  journal   = {Micromachines},
  number    = {7},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2072-666X},
  doi       = {10.3390/mi7070111},
  pages     = {111},
  year      = {2016},
  abstract  = {A plug-based microfluidic system based on the principle of the light-addressable potentiometric sensor (LAPS) is proposed. The LAPS is a semiconductor-based chemical sensor, which has a free addressability of the measurement point on the sensing surface. By combining a microfluidic device and LAPS, ion sensing can be performed anywhere inside the microfluidic channel. In this study, the sample solution to be measured was introduced into the channel in a form of a plug with a volume in the range of microliters. Taking advantage of the light-addressability, the position of the plug could be monitored and pneumatically controlled. With the developed system, the pH value of a plug with a volume down to 400 nL could be measured. As an example of plug-based operation, two plugs were merged in the channel, and the pH change was detected by differential measurement.},
  language  = {en}
}