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

Abstract

Enhanced sweat sensors lead to real-time, sustained,noninvasivetracking of sweat loss, ensure insight into individual health conditionsat the molecular level, and have obtained prominent interest for theirhopeful implementations in customized health tracking. Metal-oxide-basednanostructured electrochemical amperometric sensing materials arethe best selection for continuous sweat monitoring devices owing totheir high stability, high-sensing capacity, cost-effectiveness, miniaturization,and wide applicability. In this research, CuO thin films have beenfabricated 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 andrapid response for sweat solution. Despite the pristine film beingresponsive to the 65.50 mM sweat solution (S = 2.66),the response characteristic improves to 3.95 for the 1.0% LiL-implementedCuO film. Unmodified, 1.0% LiL and 3.0% LiL-substituted thin-filmmaterials 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 enhancedsystem that could potentially be implemented in real-life sweat-trackingadministrations. Real-time sweat loss tracking capabilities of CuOsamples was found to be promising. Derived from these outcomes, weconcluded that the fabricated nanostructured CuO-based sensing systemis a useful application for the continuous observation of sweat lossas a biological argument and compatibility with other microelectronictechnologies.