Development of an integrated electrochemical system for in vitro yeast viability testing

• Published in: Biosensors & bioelectronics 2013-02, Vol.40 (1), p.315-322
• Main Authors: Adami, Andrea, Ress, Cristina, Collini, Cristian, Pedrotti, Severino, Lorenzelli, Leandro
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Cell growth monitoring; Conductometry - instrumentation; Electrochemistry - instrumentation; Equipment Design; Equipment Failure Analysis; Food Analysis - instrumentation; Fundamental and applied biological sciences. Psychology; Integrated reference electrode; ISFET; Methods. Procedures. Technologies; Reproducibility of Results; Saccharomyces cerevisiae - isolation & purification; Sensitivity and Specificity; Systems Integration; Transistors, Electronic; Various methods and equipments; Wine - analysis; Wine - microbiology; Wine yeast
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2012.07.070

This work describes the development and testing of a microfabricated sensor for rapid cell growth monitoring, especially focused on yeast quality assessment for wine applications. The device consists of a NMOS ISFET sensor with Si3N4 gate, able to indirectly monitor extracellular metabolism through pH variation of the medium, and a solid-state reference electrode implemented with PVC membranes doped with lipophilic salts (tetrabutylammonium-tetrabutylborate (TBA-TBB) and Potassium tetrakis(4-chlorphenyl)borate (KTClpB)). The use of a solid state reference electrode enables the implementation of a large number of cell assays in parallel, without the need of external conventional reference electrodes. Microbial growth testing has been performed both in standard culture conditions and on chip at different concentrations of ethanol in order to carry out a commonly used screening of wine yeast strains. Cell growth tests can be performed in few hours, providing a fast, sensitive and low cost analysis with respect to the conventional procedures.