Battery‐powered portable instrument system for single‐cell trapping, impedance measurements, and modeling analyses

Abstract

A battery-powered portable instrument system for the single-HeLa-cell trapping and analyses is developed. A method of alternating current electrothermal (ACET) and DEP are employed for the cell trapping and the method of impedance spectroscopy is employed for cell characterizations. The proposed instrument (160 mm × 170 mm × 110 mm, 1269 g) equips with a highly efficient energy-saving design that promises approximately 120 h of use. It includes an impedance analyzer performing an excitation voltage of 0.2-2 Vpp and a frequency sweep of 11-101 kHz, function generator with the sine wave output at an operating voltage of 1-50 Vpp with a frequency of 4-12 MHz, cell-trapping biochip, microscope, and input/output interface. The biochip for the single cell trapping is designed and simulated based on a combination of ACET and DEP forces. In order to improve measurement accuracy, the curve fitting method is adopted to calibrate the proposed impedance spectroscopy. Measurement results from the proposed system are compared with results from a precision impedance analyzer. The trapped cell can be modeled for numerical analyses. Many advantages are offered in the proposed instrument such as the small volume, real-time monitoring, rapid analysis, low cost, low-power consumption, and portable application.

Single Cell Electrical Characterization Techniques

“…As a result, the red blood cells have been trapped inside microwells, thus the impedance of RBCs was measured [ 102 ]. Another DEP trapping technique was developed by Tsai et al to capture a single HeLa cell, then impedance measurement was performed [ 104 ]. Figure 5 c illustrated trapping system using DEP [ 104 ].…”

“…Another DEP trapping technique was developed by Tsai et al to capture a single HeLa cell, then impedance measurement was performed [ 104 ]. Figure 5 c illustrated trapping system using DEP [ 104 ]. Despite that microelectrical impedance spectroscopy (µ-EIS) has several advantages such as label free, real time measurement and non invasive, µ-EIS also has some drawbacks.…”

“…Reprinted with permission from [ 97 ]; ( b ) Shown 3D schematic of the µ-EIS device incorporated with micropillars structure for capture the single cells; ( c ) Schematic diagram of cell measurement using DEP cell trapping technique. Reprinted with permission from [ 104 ].…”

Smartphone-based portable biosensing system using impedance measurement with printed electrodes for 2,4,6-trinitrotoluene (TNT) detection

“…In recent years, a lot of portable sensor instruments were developed for different applications such as pH sensing, cell monitoring and food component analysis Tsai et al, 2014;Yunus et al, 2011). The portable sensor instruments integrated with miniaturized sensors and detecting circuits were designed into smaller and smaller size, which made higher request for mobility of storage and display equipment.…”

A generic microfluidic biosensor of G protein-coupled receptor activation – impedance measurements of reversible morphological changes of reverse transfected HEK293 cells on microelectrodes

“…Some approaches have focused on top down dispensing methods of transfected cells into semi-open array structures. 26 A potentially more elegant and low cost solution can be found in reverse transfection of spotted plasmid DNA. 27 This method allows the formation of cell arrays by overlaying the DNA arrays with a single cell type.…”