Sensitivity of Diamond-Capped Impedance Transducer to Tröger’s Base Derivative

Abstract

Sensitivity of an intrinsic nanocrystalline diamond (NCD) layer to naphthalene Tröger's base derivative decorated with pyrrole groups (TBPyr) was characterized by impedance spectroscopy. The transducer was made of Au interdigitated electrodes (IDE) with 50 μm spacing on alumina substrate which were capped with the NCD layer. The NCD-capped transducer with H-termination was able to electrically distinguish TBPyr molecules (the change of surface resistance within 30-60 kΩ) adsorbed from methanol in concentrations of 0.04 mg/mL to 40 mg/mL. An exponential decay of the surface resistance with time was observed and attributed to the readsorption of air moisture after methanol evaporation. After surface oxidation the NCD cap layer did not show any leakage due to NCD grain boundaries. We analyzed electronic transport in the transducer and propose a model for the sensing mechanism based on surface ion replacement.

Real-Time Monitoring of Stem Cells by Diamond-Based Impedance Sensors †

“…In addition, its surface can be covalently terminated by specific atoms or molecules which control the cell occupation, adhesion and cell differentiation [3]. In our previous studies, we have already introduced an optically transparent surface-conductive diamond thin film as a functional layer in impedance sensors for biological studies [4] and recognition of gas and chemical molecules [5,6]. In this study, an impedance sensor with the functional diamond layer deposited on gold interdigitated electrodes is employed to electrically and optically monitor the activity of adipose-derived stem cells.…”

Hydrogen-Terminated Diamond Sensors for Electrical Monitoring of Cells

“…In addition, biomolecules can be covalently attached to the diamond by various methods [5], and surface functionalization is also possible. Based on these facts a prototype of an impedance sensor and some measurement systems were developed [6,7], which can be competed with commercially available impedance measurement systems. In this paper we discuss and compare the properties of the two different measurement systems, which were employed to obtain our preliminary results on diamond-based cell impedance sensors.…”

Novel Aspect in Grain Size Control of Nanocrystalline Diamond Film for Thin Film Waveguide Mode Resonance Sensor Application

“…This technique is known as an excellent optical means to study the reactions occurring in the nanoporous waveguide layer materials. ,,− The technique has also been adopted for a label-free DNA sensing, or biochemical sensing . As a platform material for such bio/biochemical sensing, NCD is obviously the most promising because of its wide variety of excellent material properties. ,− However, the ATR-type optical sensor adopting porous NCD thin layer waveguide was not reported to date.…”