1. Laboratory
for Micro- and Nanotechnology, Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
2. Chemical
Transducers Group, Institut de Microelectrònica de Barcelona (IMB-CNM, CSIC), 08193 Bellaterra, Spain
3. Sensors & Biosensors Group, Department of Chemistry, Autonomous University of Barcelona, Edifici Cn, 08193 Bellaterra, Spain