Design and development of portable low-cost electrochemical sensors for biosystems applications

Portable sensing for point-of-care (POC) can be defined as the integration of portable smart electronic devices and microfluidic systems. Current modern electronic devices like smartphones, can achieve signal transmissions by using the built-in components as interfaces, such as camera, audio-jack, wireless module and more. On the other side, a microfluidic system miniaturizes and processes laboratory applications with increased analysis speed and efficiency. In recent years, paper-based microfluidics have become more popular due to the characteristics of paper, such as porous structure, self-pumping, hydrophilic capabilities, flexible and cost-effective. Many sensing techniques have been demonstrated to be coupled with biosensing systems for POC applications, for example, electrochemical, optical, and acoustic methods. Electrochemical method is a technique to analyze the electrical and chemical signal at a solid-liquid interface, using the balance of electrode kinetics and diffusion. In this dissertation, electrochemical will be mainly illustrated and applied for applications. Two projects related to clinical and environmental applications will be presented and discussed. In the first project, a paper-based microfluidic electrochemical sensor for blood plasma glucose measurement was developed and fabricated. The disposable sensor electrode was easy fabricated with low-cost. By integrating with potentiostat, a linear correlation was obtained with standard glucose solution ranging from 36 to 600 mg/dL. Sensor was also validated with clinical blood plasma samples with error equals to 14.830%. The second project is a smartphone-based portable nitrate sensor for field water measurement. A set of EIS-based nitrate sensor and smartphone Android application was designed and fabricated. Sensor was calibrated with nitrate standard solution at the range of 1 - 100 ppm. With data transformation, a linear correlation between impedance and nitrate concentration wasobtained and transferred and coded into Andriod application for wireless measurement through Bluetooth communication. Portable nitrate sensor was measured and calculated with an error equal to 10.559%. Later, sensor was further validated with field water samples, and results from sensor were compared to benchtop analyzer. Overall, these two projects represented the potential for low-cost, disposable paper-based biosensor provide an opportunity to improve the further low-cost, portable devices for wide-range applications. With further improvements on different selections for substrate, algorithm, and more, miniaturized portable smartphone-based systems can be achieved with better performance.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Agricultural & Biological Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Li, Wenyue

Contributors dc:contributor

• Green-Miller, Angela
• Wang, Xinlei
• Bhattarai, Rabin
• Ahmad, Irfan S.

• Low-cost
• Portable
• Electrochemical Sensor

Statement dc:rights

• Copyright 2023 Wenyue Li

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/122169

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F122169