Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub>/Polyaniline Nanocomposite in a Noninvasive Disposable Enzyme Free Glucose Sensor
Kailasa Saraswathi, M. Sai Bhargava Reddy, N. Jayarambabu, Venkateswara Rao K, T. Venkatappa Rao
Abstract
Recently, continuous glucose monitoring has gained global importance in diabetes management, leading to increased interest in noninvasive technologies as more convenient alternatives to traditional finger-pricking methods for frequent glucose monitoring. Sweat has emerged as a promising alternative, although challenges persist regarding the stability of disposable biosensors and the reliability of enzymes for detecting glucose concentration in human sweat. This study focuses on synthesizing Ti 3 C 2 T x /polyaniline (PANI; MXP2; 1% Ti 3 C 2 T x ) ratios as electrocatalysts for enzyme-free glucose sensing, aiming to address these issues in noninvasive glucose detection. Furthermore, the parent Ti 3 C 2 T x, PANI, and MXP2 were drop-coated over disposable screen-printed carbon electrodes (SPCE) to enable reliable, rapid, and easy glucose detection. The resulting MXP2, exhibiting semiconductor properties ( E g = −2.79 eV), showed excellent redox performance facilitated by its large active surface area, leading to enhanced electrocatalytic glucose oxidation. Modified PANI/SPCE, Ti 3 C 2 T x /SPCE, and MXP2/SPCE sensors demonstrated excellent sensitivity values of 576.9, 687.44, and 1241.57 μA mM –1 cm –2, respectively, along with low detection limits of 25 nM, 18 nM, and 17 nM (considered S/N = 3). These sensitivities were observed in the linear dynamic range of 1–350 μM within the potential window of −0.5 V to +0.5 V. Furthermore, the MXP2/SPCE sensor exhibited repeatability with an RSD of 0.632% under artificial sweat conditions. Real glucose detection in human sweat was performed using the fast walking task. Overall, the MXP2/SPCE sensor shows promise as a stable, reliable, disposable, and cost-effective noninvasive enzyme-free device for wearable bioelectronics.