Impedimetric Microfluidic Sensor-in-a-Tube for Label-Free Immune Cell Analysis

Analytical platforms based on impedance spectroscopy are promising for non-invasive and label-free analysis of single cells as well as of their extracellular matrix, being essential to understand cell function in the presence of certain diseases. Here, an innovative rolled-up impedimetric microfulidic sensor, called sensor-in-a-tube, is introduced for the simultaneous analysis of single human monocytes CD14+ and their extracellular medium upon liposaccharides (LPS)-mediated activation. In particular, rolled-up platinum microelectrodes are integrated within for the static and dynamic (in-flow) detection of cells and their surrounding medium (containing expressed cytokines) over an excitation frequency range from 10(2) to 5 x 10(6) Hz. The correspondence between cell activation stages and the electrical properties of the cell surrounding medium have been detected by electrical impedance spectroscopy in dynamic mode without employing electrode surface functionalization or labeling. The designed sensor-in-a-tube platform is shown as a sensitive and reliable tool for precise single cell analysis toward immune-deficient diseases diagnosis.

Automated summary

An innovative rolled-up impedimetric microfluidic sensor, named sensor-in-a-tube, is introduced for simultaneous analysis of single human monocytes CD14+ and their extracellular medium during lipopolysaccharide (LPS)-induced activation. The platform utilizes electrical impedance spectroscopy to detect the correspondence between cell activation stages and the electrical properties of the cell surrounding medium without the need for surface functionalization or labeling. The sensor-in-a-tube platform is demonstrated as a sensitive and reliable tool for precise single cell analysis towards immune-deficient diseases diagnosis.