Laser-induced disposable electrochemical devices based on Kapton adhesive tape for sensing applications

Description:
Laser-scribing technique consists of carbonizing organic substrates with a CO2 laser source, generating carbon conductive tracks [1]. This method is a simple and rapid way to fabricate electrochemical sensors [1]. Kapton adhesive tape, a polyimide substrate, stands out among the substrates [1] due to its intrinsic properties, including flexibility, low cost, and hydrophobicity [2]. Herein, new electrochemical sensors were produced using the laser-scribing technique and Kapton tape. The laser processing was submitted to the optimization and the best conditions were laser power = 8.0 % (~1.4 W), scan rate = 80.0 mm s−1, Z-distance = 13.0 mm, and distance between radiation lines = 0.04 mm. The resulting materials were characterized by Raman spectroscopy, scanning electron microscopy (SEM), and electrochemical techniques. Raman spectrum of the carbonized material had bands with carbon characteristics. Additionally, porous structures were observed in the SEM images. These porous carbon structures provide electrical conductivity to the resulting materials, opening possibilities of using them as electrochemical sensors. The sensors were engineered as a chip and characterized using hexaammineruthenium (III) and ferrocyanide as electrochemical probes. The sensors provided competitive electrochemical responses compared to commercial screen-printed electrodes. In addition, they showed great flexibility, repeatability, and storage stability. Once characterized, 3-nitrotyrosine, uric acid, and dopamine were selected as proofs-of-concept to show the analytical applicability of the sensors, demonstrating promising features for sensing applications.

[1] Lahcen, A. A., Rauf, S., Beduk, T., Durmus, c., Aljedaibi, A., Timur, s., Alshareef, H. N., Amine, A., Wolfbeis, O. S., Salama, K. N., Biosensors and Bioelectronics, 168, 112565, 2020.
[2] Wang, S., Chinnasamy, T., Lifson, M., Inci, F., Demirci, U., Trends in Biotechnology, 34, 909-921, 2016.

Speaker: Letícia Mendes - University of São Paulo
Letícia graduated in Chemistry (2016) from the Federal University of São Carlos and received a Master’s degree in Chemistry at the University of São Paulo (USP)(2018). She is currently a Ph.D. student at USP. Letícia is supervised by Professor Dr. Thiago Paixão and her works focus on the development of disposable electrochemical sensors for biological and clinical analyses involving wearable sensors. She receives financial support from São Paulo Research Foundation - FAPESP (Grant Numbers: 2018/16250-0). As part of her Ph.D., she is also working at the University of California San Diego (UCSD) in Professor Dr. Joseph Wang’s laboratory.