An impedance flow cytometry with integrated dual microneedle for electrical properties characterization of single cell

Abstract

Electrical characteristics of living cells have been proven to reveal important details about their internal structure, charge distribution and composition changes in the cell membrane, as well as the extracellular context. An impedance flow cytometry is a common approach to determine the electrical properties of a cell, having the advantage of label-free and high throughput. However, the current techniques are complex and costly for the fabrication process. For that reason, we introduce an integrated dual microneedle-microchannel for single-cell detection and electrical properties extraction. The dual microneedles utilized a commercially available tungsten needle coated with parylene. When a single cell flows through the parallel-facing electrode configuration of the dual microneedle, the electrical impedance at multiple frequencies is measured. The impedance measurement demonstrated the differential of normal red blood cells (RBCs) with three different sizes of microbeads at low and high frequencies, 100 kHz and 2 MHz, respectively. An electrical equivalent circuit model (ECM) was used to determine the unique membrane capacitance of individual cells. The proposed technique demonstrated that the specific membrane capacitance of an RBC is 9.42 mF/m⁻², with the regression coefficients, $\rho$ at 0.9895. As a result, this device may potentially be used in developing countries for low-cost single-cell screening and detection.

Keywords:

• Single-cell analysis
• impedance analysis
• microfluidic
• impedance flow cytometry

Acknowledgements

We would like to express our gratitude to Universiti Teknologi Malaysia and the Technical University of Liberec for financing this research and providing continued support. We also thank to Mr. Shafi and Mr. Nadzri from Pusat Kesihatan Universiti Teknologi Malaysia for providing the blood samples. This project is supported by the Ministry of Higher Education of Malaysia and Universiti Teknologi Malaysia under the Professional Development Research University Grant [no. Q.J130000.21A2.06E67] in the project ‘Development of Microfluidic Systems in PDMS for Microalgae Detection and Separation for Renewal Energy Application’, as well as the Ministry of Education, Youth, and Sports of the Czech Republic and the European Union (European Structural and Investment Funds Operational Program Research, Development, and Education) in the framework of the project ‘Modular platform for autonomous chassis of specialized electric vehicles for freight and equipment transportation’, Reg. No. CZ.02.1.01/0.0/0.0/16_025/0007293. The authors acknowledge the support of the Minister of Transport and Construction of the Slovak Republic and the European Union in the Transport Sector and Information Technology in the frames of the project ‘Adaptation of twenty-first century technologies for non-conventional low-emission vehicles based on composite materials’, Reg. No. NFP313010BXF3 by OPII – VA/DP/2021/9.3-01. The projects support the fabrication of the devices and electrical system, measurement of the data, demonstration of the results, preparation and evaluation of the research draft, and the financial support for the official process of the publication.

Author contributions

M.A.M. and M.R.A. are involved in the research conceptualization and methodology, and fabrication of the integrated dual microneedles–microfluidic system. M.A.M., M.R.A., M.P. and S.S.R.K. were involved in the design validity and visualization of the microchannel, microfabrication and assembly of the electrodes, as well as analysis and demonstration of the three-dimensional electrode configuration. M.A.M. and M.R.A., involved in the measurement of electrical properties. M.A.M., M.R.A., M.P. and S.S.R.K. are involved in validation, visualization, formal analysis of the research, and project administration. M.A.M., M.R.A., M.P. and S.S.R.K. involved in the writing/review and editing of the original draft preparation of the manuscript. Supervision, resources and funding acquisition of the project were managed by M.R.A., M.P. and S.S.R.K. All authors have read and agreed to the submitted version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The pre-print version of the manuscript is available at Research Square: https://assets.researchsquare.com/files/rs-1660328/v1_covered.pdf?c=1653060126. Data available on request from the authors.