title: Integrated label-free silicon nanowire sensor arrays for (bio)chemical analysis.
abstract: We present a label-free (bio)chemical analysis platform that uses all-electrical silicon nanowire sensor arrays integrated with a small volume microfluidic flow-cell for real-time (bio)chemical analysis and detection. The integrated sensing platform contains an automated multi-sample injection system that eliminates erroneous sensor responses from sample switching due to flow rate fluctuations and provides precise sample volumes down to 10 nl. Biochemical sensing is demonstrated with real-time 15-mer DNA-PNA (peptide nucleic acid) duplex hybridization measurements from different sample concentrations in a low ionic strength, and the equilibrium dissociation constant KD ≈ 140 nM has been extracted from the experimental data using the first order Langmuir binding model. Chemical sensing is demonstrated with pH measurements from different injected samples in flow that have sensitivities consistent with the gate-oxide materials. A differential sensor measurement configuration results in a 30× reduction in sensor drift. The integrated label-free analysis platform is suitable for a wide range of small volume chemical and biochemical analyses.
authors.affiliation: BIOS/Lab on a Chip Group, MESA+ Institute for Nanotechnology, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands.
authors.forename: Arpita
authors.initials: A
authors.lastname: De
authors.forename: Jan
authors.initials: J
authors.lastname: van Nieuwkasteele
authors.forename: Edwin T
authors.initials: ET
authors.lastname: Carlen
authors.forename: Albert
authors.initials: A
authors.lastname: van den Berg
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002021:Buffers; D004247:DNA / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D036103:Nanotechnology / Q000295:instrumentation*; D053770:Nanowires; D009693:Nucleic Acid Hybridization; D020135:Peptide Nucleic Acids / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D018511:Systems Integration; D014173:Transistors, Electronic
chemical_list: D002021:Buffers; D020135:Peptide Nucleic Acids; D004247:DNA; D012825:Silicon