A Proof-of-Concept Electrochemical Skin Sensor for Simultaneous Measurement of Glial Fibrillary Acidic Protein (GFAP) and Interleukin-6 (IL-6) for Management of Traumatic Brain Injuries

Abstract

This work demonstrates the use of a noninvasive, sweat-based dual biomarker electrochemical sensor for continuous, prognostic monitoring of a Traumatic Brain Injury (TBI) with the aim of enhancing patient outcomes and reducing the time to treatment after injury. A multiplexed SWEATSENSER was used for noninvasive continuous monitoring of glial fibrillary acidic protein (GFAP) and Interleukin-6 (IL-6) in a human sweat analog and in human sweat. Electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) were used to measure the sensor response. The assay chemistry was characterized using Fourier Transform Infrared Spectroscopy (FTIR). The SWEATSENSER was able to detect GFAP and IL-6 in sweat over a dynamic range of 3 log orders for GFAP and 2 log orders for IL-6. The limit of detection (LOD) for GFAP detection in the sweat analog was estimated to be 14 pg/mL using EIS and the LOD for IL-6 was estimated to be 10 pg/mL using EIS. An interference study was performed where the specific signal was significantly higher than the non-specific signal. Finally, the SWEATSENSER was able to distinguish between GFAP and IL-6 in simulated conditions of a TBI in human sweat. This work demonstrates the first proof-of-feasibility of a multiplexed TBI marker combined with cytokine and inflammatory marker detection in passively expressed sweat in a wearable form-factor that can be utilized toward better management of TBIs. This is the first step toward demonstrating a noninvasive enabling technology that can enable baseline tracking of an inflammatory response.

Effect of Applied AC Voltage on the Performance of Non-Faradaic Impedimetric Biosensors

“…18,19 To the best of authors' knowledge, the effect of applied AC voltage on the linearity of bare Au-IDEs during non-faradaic EIS measurements was not investigated in the past, nor was the effect of applied AC voltage on the performance of fully functionalized biosensors for the detection of biomarkers. [20][21][22][23] As previously mentioned, the commonly used AC voltage in non-faradaic EIS measurements is 10 mV with few researchers attempted biosensing with an applied AC voltage of 50 mV. In this regard, we report for the first time the effect of applied AC voltage on bare Au-IDEs electrodes using non-faradaic EIS mode.…”

Review on the neuron damage parameters in patients with end-stage renal disease

“…GFAP levels could reflect neuronal damage in obese of ESRD [65]. GFAP circulating levels have been described in the context of traumatic brain injury [66]. Increased GFAP has been shown to alter with changing hormone levels [67].…”

Special Issue “Women in Biosensors”—The First Edition

“…Non-invasive approaches for obtaining important biochemical information are detailed in the manuscript submitted by Dr. Shalini Prasad’s team [ 2 ]. The team demonstrated the use of a noninvasive, sweat-based, dual biomarker sensor by continuous monitoring of glial fibrillary acidic protein (GFAP) and interleukin-6 (IL-6) in a human sweat analog and in human sweat.…”

“…Using EIS, the SWEATSENSER was able to detect GFAP and IL-6 in the sweat analog with an estimated limit of detection (LOD) for GFAP detection of 14 pg mL −1 and for IL-6 detection of 10 pg mL −1 . The sensor demonstrated the ability to detect the relative reactivities of GFAP and IL-6 in simulated profiles of mild and moderate TBIs in human sweat [ 2 ].…”