A microwell-based impedance sensor on an insertable microneedle for real-time in vivo cytokine detection

Abstract

Impedance-based protein detection sensors for point-of-care diagnostics require quantitative specificity, as well as rapid or real-time operation. Furthermore, microfabrication of these sensors can lead to the formation of factors suitable for in vivo operation. Herein, we present microfabricated needle-shaped microwell impedance sensors for rapid-sample-to-answer, label-free detection of cytokines, and other biomarkers. The microneedle form factor allows sensors to be utilized in transcutaneous or transvascular sensing applications. In vitro, experimental characterization confirmed sensor specificity and sensitivity to multiple proteins of interest. Mechanical characterization demonstrated sufficient microneedle robustness for transcutaneous insertion, as well as preserved sensor function postinsertion. We further utilized these sensors to carry out real-time in vivo quantification of human interleukin 8 (hIL8) concentration levels in the blood of transgenic mice that endogenously express hIL8. To assess sensor functionality, hIL8 concentration levels in serum samples from the same mice were quantified by ELISA. Excellent agreement between real-time in vivo sensor readings in blood and subsequent ELISA serum assays was observed over multiple transgenic mice expressing hIL8 concentrations from 62 pg/mL to 539 ng/mL.

Integrated biosensors for monitoring microphysiological systems

“…144,145 In this article, a microwell-based impedance sensor was developed for real-time and in vivo detection of cytokine (interleukin 8, IL-8). 146 This kind of sensor could be applied to real-time and continuous monitoring of cell secretome of MPSs.…”

Microneedle-based transdermal detection and sensing devices

“…This microneedle in real-time monitored the IL-8 levels in a mouse model that endogenously expressed IL-8, and the results were comparable to those measured by the ELISA gold standard approach. 112…”

“…84 Electronic analytical techniques are usually flexibly applied to microneedles, such as cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), chronoamperometry, and amperometry. 141,142 So far, microneedle-based electronic platforms are mostly applied to detections of ions (pH values, 143 Na + , 50 and K + 118 ), small molecules (glucose, 30,122,124,144 lactate, 123 and ascorbic acid 139 ), nucleic acids, 129 and proteins (cytokines 112,139 and enzymes 145 ). For example, tyrosinase (TYR) is a polyphenol oxidase involved in melanin production, whose accumulation leads to the biogenesis of melanoma.…”

“…This microneedle in real-time monitored the IL-8 levels in a mouse model that endogenously expressed IL-8, and the results were comparable to those measured by the ELISA gold standard approach. 112 Endogenous antibody detection is of particular interest for indication of vaccination efficacies and disease prognosis, and, in some cases, the epidemiological investigation of infectious diseases. Wang et al proposed an immune sandwich-based microneedle array for ultrasensitive in situ detection of antibodies and cytokines.…”

Investigating the Electric Field Lysis of Exosomes Immobilized on the Screen-Printed Electrode and Electrochemical Sensing of the Lysed-Exosome-Derived Protein

“…EIS is especially useful for accurately estimating low protein concentrations. This makes the technique more applicable and practical when working with small sample volumes [ 26 , 27 ]. In EIS, the cell under test is perturbed with a small voltage and the corresponding current is measured.…”