Carbon fiber based electrochemical sensor for sweat cortisol measurement

Abstract

This study examines the use of a conductive carbon fiber to construct a flexible biosensing platform for monitoring biomarkers in sweat. Cortisol was chosen as a model analyte. Functionalization of the conductive carbon yarn (CCY) with ellipsoidal Fe2O3 has been performed to immobilize the antibodies specific to cortisol. 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-Hydroxysuccinimide (NHS) chemistry has been used to immobilize the antibodies onto the Fe2O3 modified CCY. Crystallinity, structure, morphology, flexibility, surface area, and elemental analysis were studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, Field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FE-SEM/EDS) and Brunauer–Emmett–Teller (BET) analysis. Mechanical properties of the fiber such as tensile strength, young’s modulus have also been investigated. Under optimal parameters, the fabric sensor exhibited a good linearity (r2 = 0.998) for wide a linear range from 1 fg to 1 μg with a detection limit of 0.005 fg/mL for the sensitive detection of cortisol. Repeatability, reliability, reproducibility, and anti-interference properties of the current sensor have been investigated. Detection of cortisol levels in human sweat samples has also been investigated and the results were validated with commercial chemiluminescence immunoassay (CLIA) method.

Extended gate field-effect-transistor for sensing cortisol stress hormone

“…Recently, there has been an increasing interest in sensing cortisol biomarker in biofluids for numerous diseases related to the stress. As the secreted cortisol enters into the circulatory system, it can be found in detectable quantities in several biofluids in human body including saliva, sweat and urine 8 . The cortisol circadian rhythm (Fig.…”

Textile sensors platform for the selective and simultaneous detection of chloride ion and pH in sweat

“…On the other hand, wearable chemical sensors are at an early stage of development even if they represent a powerful tool to monitor human physiological parameters in a real-time, non-invasive and accurate manner. A number of new chemical sensors are proposed in the literature for the detection of biochemical markers like dopamine 21 , adrenaline 22 , 23 , cortisol 24 , glucose 25 , lactate 26 , phenolic compounds 27 , 28 , and electrolytes 29 – 32 with the aim of providing new tools for monitoring human health, physical exertion, fatigue and mental accuracy. An interesting approach has been proposed by Gao et al based on a fully integrated and mechanically flexible sensor array for multiplexed sweat analysis, which selectively and simultaneously measures perspiration electrolytes (sodium and potassium ions) and metabolites (glucose and lactate) 33 .…”

Stress Monitoring and Recent Advancements in Wearable Biosensors

“…As seen in Figure 2D , SKINTRONICS is a multilayered device with a wear time of up to 7 h. The group was able to achieve galvanic skin response results comparable to those of commercially available devices with the same purpose, but with the added advantage of offering long-term, hands-free use ( Kim et al, 2020 ). Other skin-interfaced sensing platforms are in development, indicating a trend toward flexible sensing ( Sekar et al, 2019 ; Kim et al, 2020 ).…”