Measuring the viscosity of glycerin solutions in very small samples using Sciospec ISX-3 Impedance Analyzer
Measuring the viscosity of very small sample volumes is of high interest in many fields especially in miniaturized and micro-fluidic systems. This application note describes an approach using the change of the impedance spectrum of a Thickness Shear Mode Resonator in combination with a sophisticated fitting algorithm. The simple setup of the measuring system enables easy integration in existing micro-fluidic settings with almost no adaption. As validation of the Sciospec ISX-3 a comparison to theoretical values and to a commercially available vector network analyzer on the same setup is provided.
The measurement of the viscosity is very well known for sample volumes larger than a couple milliliters. The standard viscometers use either rotating parts, a flow through, a capillary system or falling spheres. This application note describes an example of measuring smaller sample volumes with no need for mechanical parts.
Online monitoring of deposition or coating processes is highly relevant in a variety of fields including biocompatible coatings for medical implants. As of now mostly “simple” resonance tracking of quartz crystal microbalances is used for these purposes. The joint research project by AG Mayr, Leibniz Institute of Surface Modification Leipzig1 and Sciospec was aiming for more specific insights into the process itself. Especially nano-structural formation and adhesion parameters are of high interest. This application note describes the first step of data acquisition and parameter estimation.
Robust multi-parametric sensor system for the online detection of microbial biofilms in industrial applications — Preliminary examination
Biofilm formation can cause serious health hazards, mostly due to the uncontrolled release of pathogens. This can generate several problems in industrial facilities, e.g., in the food industry. The aim of the present study was to develop and implement a multi-parametric sensor system to monitor biofilm formation in laboratory as well as industrial set-ups. To minimize cross sensitivity or interference, the device was based on a combination of different measurement principles. Micro-organisms were initially cultivated in a laboratory scale reactor. Afterwards, biofilm formation will be studied with each prototype of the multi-parametric sensor followed by final tests on an industrial scale.
The development of biosensors to identify the molecular markers of specific genes is fundamental for the implementation of new techniques that allow the detection of specific DNA sequences in a fast, economic, and simple way. Electrical Bioimpedance Spectroscopy (EBiS) has been used for the diagnosis and monitoring of human pathologies, and is recognized as a safe, fast, reusable, easy, and inexpensive technique. This study proves the development of a complementary DNA (cDNA) biosensor based on measurements of EBiS and of the immobilization of DNA without chemical modifications, and presents the evaluation of its potential usefulness in the detection of the gene expression of an inflammation characteristic biomarker, NLRP3, is presented. The obtained results demonstrate that EBiS can be used to identify different gene expression patterns, and measurements were compared with Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) and validated by Quantitative Polymerase Chain Reaction (qPCR). These results indicate the technical feasibility of a biosensor of specific genes through bioimpedance measurements in the immobilization of cDNA.