Wearable Cortisol Aptasensor for Simple and Rapid Real-Time Monitoring

Abstract

The necessity of managing stress levels is becoming increasingly apparent as the world suffers from different kinds of stresses including the extent of pandemic, the corona virus disease 2019 . Cortisol, a clinically confirmed stress hormone related to depression and anxiety, affects individuals mentally and physically. However, current cortisol monitoring methods require expert personnel, large and complex machines, and long time for data analysis. Here, we present a flexible and wearable cortisol aptasensor for simple and rapid cortisol real-time monitoring. The sensing channel was produced by electrospinning conducting polyacrylonitrile (PAN) nanofibers (NFs) and subsequent vapor deposition of carboxylated poly(3,4-ethylenedioxythiophene) (PEDOT). The conjugation of the cortisol aptamer on the PEDOT-PAN NFs provided the critical sensing mechanism for the target molecule. The sensing test was performed with a liquid-ion gated field-effect transistor (FET) on a polyester (polyethylene terepthalate). The sensor performance showed a detection limit of 10 pM (<5 s) and high selectivity in the presence of interference materials at 100 times higher concentrations. The practical usage and real-time monitoring of the cortisol aptasensor with a liquid-ion gated FET system was demonstrated by successful transfer to the swab and the skin. In addition, the real-time monitoring of actual sweat by applying the cortisol aptasensor was also successful since the aptasensor was able to detect cortisol approximately 1 nM from actual sweat in a few minutes. This wearable biosensor platform supports the possibility of further application and on-site monitoring for changes of other numerous biomarkers.

Open‐Bandgap Graphene‐Based Field‐Effect Transistor Using Oligo(phenylene‐ethynylene) Interfacial Chemistry

“…In particular, n-type transistors cannot be utilized for biosensors due to the occurrence of damage to biomolecules by radicals. [45] The transfer curves indicated the charge density and the movement of the Dirac point (Figure 4f). The OGMFET displayed a Dirac point at 0.35 V, while the Dirac point was negatively shifted to 0.15 V (ΔV g = À 0.2 V) after magainin I conjugation due to the positive charge of magainin I.…”

A Portable Graphene Micropatterned Field-Effect Transistor Device for Rapid Real-Time Monitoring of Serotonin

“…The liquid-ion gated FET system was suitably verified of the operation in the 𝑝-type region because electron transfer was induced by oxygen, and the biomolecules were damaged by the radicals generated in the 𝑛-type region in the liquid phase. [23]. The transfer curves showed the shifted Dirac point as a minimum gating effect depending on the surface modifications of the graphene surface, which indicated a change in the charge carrier density caused by PDA and SAb [Fig.…”

Integrated Aptasensor Array for Sweat Drug Analysis

“…Aptamer-based sensors have presented great significance in drug screening, biomedical diagnosis, forensic analysis, and environmental monitoring . For instance, Kwon and co-workers investigated a flexible and wearable cortisol aptasensor for the real-time monitoring of cortisol in actual sweat. Undoubtedly, combined with the advantages of wearable aptasensors and electrochemical techniques, wearable electrochemical aptasensors for sweat-based analysis could provide wide application prospects for the development of new cost-effective sensing platforms for drug analysis …”