Integration of a Droplet-Based Microfluidic System and Silicon Nanoribbon FET Sensor

We present a novel microfluidic system that integrates droplet microfluidics with a silicon nanoribbon field-effect transistor (SiNR FET), and utilize this integrated system to sense differences in pH. The device allows for selective droplet transfer to a continuous water phase, actuated by dielectrophoresis, and subsequent detection of the pH level in the retrieved droplets by SiNR FETs on an electrical sensor chip. The integrated microfluidic system demonstrates a label-free detection method for droplet microfluidics, presenting an alternative to optical fluorescence detection. In this work, we were able to differentiate between droplet trains of one pH-unit difference. The pH-based detection method in our integrated system has the potential to be utilized in the detection of biochemical reactions that induce a pH-shift in the droplets.

[1]  Pelin Kubra Isgor,et al.  Microfluidic droplet content detection using integrated capacitive sensors , 2015 .

[2]  Helen Song,et al.  Reactions in droplets in microfluidic channels. , 2006, Angewandte Chemie.

[3]  P. Bergveld,et al.  Operation of chemically sensitive field-effect sensors as a function of the insulator-electrolyte interface , 1983, IEEE Transactions on Electron Devices.

[4]  Helene Andersson Svahn,et al.  Droplet microfluidics--a tool for single-cell analysis. , 2012, Angewandte Chemie.

[5]  K. R. Williams,et al.  Etch rates for micromachining processing-Part II , 2003 .

[6]  H. Craighead.  Future lab-on-a-chip technologies for interrogating individual molecules , 2006, Nature.

[7]  Akira Matsumoto,et al.  Current and emerging challenges of field effect transistor based bio-sensing. , 2013, Nanoscale.

[8]  D. E. Yates,et al.  Site-binding model of the electrical double layer at the oxide/water interface , 1974 .

[9]  A. Theberge,et al.  Microdroplets in microfluidics: an evolving platform for discoveries in chemistry and biology. , 2010, Angewandte Chemie.

[10]  Joseph M Azzarelli,et al.  Nanowire Chemical/Biological Sensors: Status and a Roadmap for the Future. , 2015, Angewandte Chemie.

[11]  Rashid Bashir,et al.  Label-free electrical detection of pyrophosphate generated from DNA polymerase reactions on field-effect devices. , 2012, The Analyst.

[12]  Shyamsunder Erramilli,et al.  Surface-modified silicon nano-channel for urea sensing , 2008 .

[13]  Haakan N Joensson,et al.  Multiplex analysis of enzyme kinetics and inhibition by droplet microfluidics using picoinjectors. , 2013, Lab on a chip.

[14]  L. Mazutis,et al.  Quantitative and sensitive detection of rare mutations using droplet-based microfluidics. , 2011, Lab on a chip.

[15]  Mark A. Reed,et al.  Silicon Nanowire Field-Effect Transistors—A Versatile Class of Potentiometric Nanobiosensors , 2015, IEEE Access.

[16]  Mark A. Reed,et al.  Direct, rapid, and label-free detection of enzyme-substrate interactions in physiological buffers using CMOS-compatible nanoribbon sensors. , 2014, Nano letters.

[17]  T. Schmidt,et al.  Effect of microwave-assisted silanization on sensing properties of silicon nanoribbon FETs , 2015 .

[18]  A. van den Berg,et al.  Label-free, high-throughput, electrical detection of cells in droplets. , 2012, The Analyst.

[19]  Chengzhou Zhu,et al.  Electrochemical Sensors and Biosensors Based on Nanomaterials and Nanostructures , 2014, Analytical chemistry.

[20]  Tza-Huei Wang,et al.  Microfluidic continuous flow digital loop-mediated isothermal amplification (LAMP). , 2015, Lab on a chip.

[21]  Cheng-Chih Hsu,et al.  Multiple Silicon Nanowires with Enzymatic Modification for Measuring Glucose Concentration , 2015, Micromachines.

[22]  G. Whitesides,et al.  Fabrication of microfluidic systems in poly(dimethylsiloxane) , 2000, Electrophoresis.

[23]  Andrew D Griffiths,et al.  A completely in vitro ultrahigh-throughput droplet-based microfluidic screening system for protein engineering and directed evolution. , 2012, Lab on a chip.

[24]  D. Weitz,et al.  Fluorescence-activated droplet sorting (FADS): efficient microfluidic cell sorting based on enzymatic activity. , 2009, Lab on a chip.

[25]  Anita Topkar,et al.  Effect of electrolyte exposure on silicon dioxide in electrolyte-oxide-semiconductor structures , 1993 .

[26]  Mengsu Yang,et al.  Silicon nanowires for high-sensitivity glucose detection , 2006 .

[27]  Andreas Offenhäusser,et al.  Label-free detection of biomolecules by a field-effect transistor microarray biosensor with bio-functionalized gate surfaces , 2006 .

[28]  C. Toumazou,et al.  Simultaneous DNA amplification and detection using a pH-sensing semiconductor system , 2013, Nature Methods.

[29]  Helen Song,et al.  Millisecond kinetics on a microfluidic chip using nanoliters of reagents. , 2003, Journal of the American Chemical Society.