A Novel Modular Device for Biological ImpedancernMeasurements: The Differential Impedimetric SensorrnCell (DISC)

摘要

For medical diagnostics, food-safety analysis, and detection of environmentalrnpollutants, simultaneous detection and quantification of multiple targetrnmolecules can be a great advantage. Impedimetric measurements usingrnmolecularly imprinted polymers (MIPs), antibodies or aptamers as biomimeticrnsensors are becoming a well-established technique for detecting, quantifying,rnand analyzing various biological targets such as DNA, proteins, and smallrnmolecules. The most commonly implemented systems use non-Faradaicrnimpedance spectroscopy. Adding a redox probe such as silver/silver chloridernallows for the use of Faradaic impedance spectroscopy techniques usingrnredox-active molecules such as ferricyanide thereby extending the range ofrnpossible applications. Furthermore, the ability to perform differential measurementsrnallows for the use of undiluted patient samples which significantlyrnsimplifies sample preparation. Therefore, adapting this low-cost technique tornsimultaneously perform differential measurements on multiple targets andrnmaking it easy to use has great potential in a wide range of applications. Inrnthis work, a system that meets these requirements is successfully designedrnand fabricated. Up to eight different targets can be quasi-simultaneouslyrnanalyzed. Furthermore, the system is validated against a high-resolutionrndielectric spectrometer (Novocontrol, Alpha analyzer) using well-characterizedrnsamples at different temperatures over the whole frequency range (10 Hz–rn100 kHz).