title: Non-Faradaic electrochemical detection of protein interactions by integrated neuromorphic CMOS sensors.
abstract: Electronic detection of the binding event between biotinylated bovine serum albumen (BSA) and streptavidin is demonstrated with the chemoreceptive neuron MOS (CnuMOS) device. Differing from the ion-sensitive field-effect transistors (ISFET), CnuMOS, with the potential of the extended floating gate determined by both the sensing and control gates in a neuromorphic style, can provide protein detection without requiring analyte reference electrodes. In comparison with the microelectrode arrays, measurements are gathered through purely capacitive, non-Faradaic interactions across insulating interfaces. By using a (3-glycidoxypropyl)trimethoxysilane (3-GPS) self-assembled monolayer (SAM) as a simple covalent link for attaching proteins to a silicon dioxide sensing surface, a fully integrated, electrochemical detection platform is realized for protein interactions through monotone large-signal measurements or small-signal impedance spectroscopy. Calibration curves were created to coordinate the sensor response with ellipsometric measurements taken on witness samples. By monitoring the film thickness of streptavidin capture, a sensitivity of 25ng/cm2 or 2A of film thickness was demonstrated. With an improved noise floor the sensor can detect down to 2ng/(cm2mV) based on the calibration curve. AC measurements are shown to significantly reduce long-term sensor drift. Finally, a noise analysis of electrochemical data indicates 1/f(alpha) behavior with a noise floor beginning at approximately 1Hz.
authors.affiliation: School of Electrical and Computer Engineering, Cornell University Ithaca, 323 Phillips Hall, Ithaca, NY 14853 USA. bcj7@cornell.edu
authors.forename: Blake C
authors.initials: BC
authors.lastname: Jacquot
authors.forename: Nini
authors.initials: N
authors.lastname: Muñoz
authors.forename: Darren W
authors.initials: DW
authors.lastname: Branch
authors.forename: Edwin C
authors.initials: EC
authors.lastname: Kan
mesh_terms: D040761:Biomimetic Materials; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D016571:Neural Networks, Computer; D025941:Protein Interaction Mapping / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012666:Semiconductors; D012680:Sensitivity and Specificity; D018511:Systems Integration