Monitoring of Saccharomyces cerevisiae Cell Proliferation on Thiol-Modified Planar Gold Microelectrodes Using Impedance Spectroscopy

Abstract

An impedance spectroscopic study of the interaction between thiol-modified Au electrodes and Saccharomyces cerevisiae of strain EBY44 revealed that the cells formed an integral part of the interface, modulating the capacitive properties until a complete monolayer was obtained, whereas the charge transfer resistance ( R ct) to the redox process of [Fe(CN)6] 3-/4- showed a linear relationship to the number of cells even beyond the monolayer coverage. R ct showed strong pH dependence upon increasing the pH of the utilized buffer to 7.2. Upon addition of S. cerevisiae cells at pH 7.2, the obtained value of R ct showed over 560% increase with respect to the value obtained on the same thiol-modified electrode without cells. It was demonstrated that real-time monitoring of S. cerevisiae proliferation, with frequency-normalized imaginary admittance (real capacitance) as the indicator, was possible using a miniaturized culture system, ECIS Cultureware, with integrated planar cysteamine-modified Au microelectrodes. A monolayer coverage was reached after 20-28 h of cultivation, observed as an approximately 15% decrease in the real capacitance of the system.

A compact multifunctional microfluidic platform for exploring cellular dynamics in real-time using electrochemical detection

“…The optimized cleaning procedure for Au electrodes, as previously presented elsewhere, comprises both a chemical and electrochemical step. 44,45 The complete cleaning, as evaluated in an electrochemical batch cell, renders electrodes with a highly reproducible behaviour. 25,26 During system assembly (as described in the Experimental section), each microelectrode chip undergoes chemical cleaning prior to integration with microuidics, since it is not amenable for a closed microuidic system due to strong gas evolution during the process.…”

“…30,44 We have previously shown the suitability of EIS for monitoring the progress of yeast cell sedimentation 44 as a means to evaluate when the cell seeding is complete allowing initiation of the assay. Aer yeast sedimentation was achieved, the amperometric monitoring of the intracellular redox metabolism was performed under microuidic conditions by using the menadione/ferricyanide double mediator system.…”

Functional and Selective Bacterial Interfaces Using Cross-Scaffold Gold Binding Peptides

“…68,69 However, these techniques are non-specific and rely on general chemical and physical factors including: adsorption, covalent bonding, entrapment, encapsulation and crosslinking. 70 For example, Yang et al 71 attached the bacterium Salmonella typhimurium to a gold electrode surface through simple adsorption, while Heiskanen et al 11 conjugated yeast cells to thiol-modified gold microelectrodes. Traditionally, cell attachment to gold, as well as to other surfaces, is not direct, but rather tethered or adhered to the surface through a general physiochemical interaction.…”

“…[1][2][3][4][5] In particular, the conjugation of biomolecules (proteins, enzymes, deoxyribonucleic acid (DNA), and lipids) as well as living cells to both flat and structured gold has been extensively documented. [6][7][8][9][10][11][12][13][14][15][16] Traditionally, biomolecule coupling to gold (or other substrates) is often facilitated by a cross-linking agent and rarely directly to the gold surface itself. Integration of a gold-binding peptide into a biomolecule of interest allows utilization of more complex chemistry and offers the advantage of direct integration with the surface.…”

Development of a Lab-on-a-Chip Device for Rapid Nanotoxicity Assessment In Vitro

“…The chip containing the paper strip was secured in a petri dish covered with paraffin film for appropriate time. -SH group of cysteine will covalently bind to the gold surface and develops self-assembled monolayer (SAM) and the free amine group will favor the cell attachment by attracting carboxylic groups available on the cell membrane [108].…”