Nanostructured CuO Thin-Film-Based Conductometric Sensors for Real-Time Tracking of Sweat Loss

Abstract

Enhanced sweat sensors lead to real-time, sustained, noninvasive tracking of sweat loss, ensure insight into individual health conditions at the molecular level, and have obtained prominent interest for their hopeful implementations in customized health tracking. Metal-oxide-based nanostructured electrochemical amperometric sensing materials are the best selection for continuous sweat monitoring devices owing to their high stability, high-sensing capacity, cost-effectiveness, miniaturization, and wide applicability. In this research, CuO thin films have been fabricated by successive ionic layer adsorption and reaction technique (SILAR) with and without the addition of Lawsonia inermis L. (Henna, (LiL)) leaf extract (C10H6O3, 2-hydroxy-1,4-naphthoquinone) with a high-sensitive and rapid response for sweat solution. Despite the pristine film being responsive to the 65.50 mM sweat solution (S = 2.66), the response characteristic improves to 3.95 for the 1.0% LiL-implemented CuO film. Unmodified, 1.0% LiL and 3.0% LiL-substituted thin-film materials assure considerable linearity with linear regression ranges, R 2, of 0.989, 0.997, and 0.998, respectively. It is noteworthy here that this research aims to determine an enhanced system that could potentially be implemented in real-life sweat-tracking administrations. Real-time sweat loss tracking capabilities of CuO samples was found to be promising. Derived from these outcomes, we concluded that the fabricated nanostructured CuO-based sensing system is a useful application for the continuous observation of sweat loss as a biological argument and compatibility with other microelectronic technologies.

Conductometric Flexible CuO-Based Sweat-Loss Monitoring Sensor for Future Wearable Technology in Healthcare

“…In connection with these features, the sensing ability of films can differentiate their properties. It has been reported that the morphological change strengthens the cohesion effect and plays a role in the change of the contact angle …”

“…We characterized the sweat loss tracking performance of the fabricated flexible devices by providing four different concentrations of artificial sweat samples that were dropped onto the devices. The sensing-response values are defined as eq S = I n o m − I i I i where S is the sensing response value of the CuO thin film material to the artificial sweat solutions. I nom is the stable conductivity of the devices in the sweat solution implementation; I i is the steady conductivity of the device in air (without artificial sweat solution implementation).…”

“…This increased interaction between the artificial-sweat sample and the designed device surface is potent for the sensing system and causes a significant sensing characteristic. Inhalation of severe sweat-electrolytes in the sensing systems is important to enhance the active sites on the device structure and improve sensing performances. , It indicates that the enhanced sweat-sensing response for the changed contact angle is due to the adsorption of more ions on the film surface.…”