pH is a fundamental biological parameter. Reactions including nucleotide and protein synthesis involve proton exchanges that can be reflected as pH modifications in small volumes. Silicon nanowires (SiNWs) promise low footprints, high sensitivities and fast responses. The pH sensing layer is an oxide able to install a chemical equilibrium with the protons in solution. SiO₂ is the most widely used oxide but it provides a limited linearity (pH ranges pH>5). ALD deposited Al₂O₃ and HfO₂ can provide higher linearity and sensitivity in larger pH ranges (2 to 10). Our aim is the fabrication of SiNWs using a top- down approach based on electron beam lithography and wet etching integrating ALD deposition of different oxides. Integration with μ-fluidics and actuating electrodes for acid/base titration can provide an independent pH senor.

Nano-wires as wide range pH sensors for integration with μ-fluidics and future actuating electrodes for acid/base titration

Serena Rollo, César Pascual García
Luxembourg Institute of Science and Technology (LIST), Luxembourg
University of Twente, Netherlands

Contact information:

Wouter Olthuis

Project carried out by:
Serena Rollo

Daily supervisor:
César Pascual García


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