Mechanical Engineering Faculty Publications and Presentations
Document Type
Article
Publication Date
5-17-2025
Abstract
In this research, an interdigitated gear-shaped working electrode is presented for cortisol sensing. Overall, the sensor was designed in a three-electrode system and was fabricated using direct laser scribing. A synthesized conductive ink based on graphene and polyaniline was further employed to enhance the electrochemical performance of the sensor. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were employed for physicochemical characterization of the laser-induced graphene (LIG) sensor. Cortisol, a biomarker essential in detecting stress, was detected both in phosphate-buffered saline (PBS, pH = 7.4) and human serum within a linear range of 100 ng/mL to 100 µg/mL. Ferri/ferrocyanide was employed as the redox probe to detect cortisol in PBS. The electrochemical performance of the developed sensor was assessed via differential pulse voltammetry (DPV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. The electrochemical performance demonstrates high sensitivity and selectivity alongside strong repeatability (relative standard deviation (RSD) = 3.8%, n = 4) and reproducibility (RSD = 5.85%, n = 5). Overall, these results highlight the sensor’s reliability, high sensitivity, and repeatability and reproducibility in the detection of cortisol. The sensor successfully detected cortisol in the complex medium of human serum and effectively distinguished it in a ternary mixture containing cortisol and dopamine. Also, the use of direct laser writing on Kapton film makes the approach cost-effective and thus disposable, making it suitable for chronic stress diagnostics and neurological research applications.
Recommended Citation
Sarkar, Pritu Parna, Ali Ashraf, Ahmed Hasnain Jalal, Fahmida Alam, and Nazmul Islam. 2025. "A Highly Sensitive Electrochemical Immunosensor for Cortisol Detection" Biosensors 15, no. 5: 321. https://doi.org/10.3390/bios15050321
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Publication Title
Biosensors
DOI
10.3390/bios15050321
Comments
© 2025 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).