Session: 13-04-02: Applications of Micro and Nano Systems in Medicine and Biology II

Paper Number: 114031

114031 - Graphene Nanoparticle Modified Laser Engraved Kapton Sensor for Environmental Estrogen Detection 

Chemicals that can interfere with endocrine (or hormonal) systems known as endocrine disruptors, mimic or interfere with the body’s hormones.  Hormone disruptors have the ability to wreck any function in the body that is regulated by hormones. Endocrine disruptors may specifically be linked to the emergence of cognitive and brain development issues, severe attention deficit disorder, and learning difficulties. 17-β estradiol is one of the main chemicals with a significant endocrine disruptor activity. This steroid hormone causes fish and birds to develop their thyroids improperly, interfering with animal life. In crustaceans, fish, birds, and reptiles, the substance can also cause immunological harm, sexual dysfunction, and reduced fertility. 17-β estradiol can also cause serious congenital abnormalities in children and can decrease male fertility. In this paper, we have developed a graphene-based flexible electrochemical immune sensor for the rapid detection of 17-β estradiol in phosphate buffer saline (PBS) buffer solution. The irreversible oxidation of the molecule's phenol group serves as the basis for the electrochemical determination of 17-βestradiol. We used Kapton as a substrate for the sensor, and Universal Laser System to engrave the electrodes on the substrate. Silver Ink has been used as contact pads. Due to high conductivity, electrochemical stability, and good biocompatibility, graphene-conductive polyaniline ink (G-PANI) was used to modify the working electrode area. The combined actions of graphene and PANI significantly increased the immunosensor's current responsiveness. In our proposed sensor, estrogen is detected via the binding interaction between the hormone and its receptor, which allows for excellent selectivity. The surface modification involves ozonolysis to introduce the -COOH- group in the sensor, and crosslinking between EDC ((1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride)), and NHS (N-hydroxysuccinimide) for efficient conjugation to primary amines. Furthermore, a very sensitive detection in a wide range of concentrations has been achieved using the electrochemical impedance spectroscopy (EIS) approach. Electrochemical impedance spectroscopy (EIS) provides significant information on interfacial reactions. In a typical Nyquist diagram, the spectrum is represented by a semicircle that corresponds to the charge transfer resistance, Rct, followed by a linear section. The linear portion is the consequence of the diffusion of redox probes from the solution to the interface, and the diameter of a semicircle is a reflection of the magnitude Rct. The relative impedance variations in the EIS test also allow for the detection of estrogen hormones. The laser-engraved Kapton sensor with modified graphene polyaniline ink (LEK\G-PANI) has impedance change with excellent linearity from 0.244 ng/ml to 4000 ng/ml with a limit of detection (LOD) is 1.935 ng/ml(s/n=3) when testing17-β estradiol in PBS (1x) buffer solution.

 

Presenting Author: Dipannita Ghosh UNIVERSITY OF TEX RIO GRANDE VALL

Presenting Author Biography: Dipannita Ghosh is currently a graduate teaching assistant in the Electrical Engineering Department. Her research interest includes developing nanomaterials, bio, and immune sensors.

Authors:

Dipannita Ghosh UNIVERSITY OF TEX RIO GRANDE VALL
Saydur Rahman University of Texas Rio Grande Valley
Ali Asharf University of Texas Rio Grande Valley
Nazmul Islam University of Texas Rio Grande Valley