Date of Award

2023-08-01

Degree Name

Doctor of Philosophy

Department

Electrical Engineering

Advisor(s)

Robert C. Roberts

Abstract

This PhD dissertation research has developed a simple, miniaturized, sensitive, selective, reproducible, and disposable 3D (inkjet printed – additive manufacturing technology) gold (Au) plated electrochemical sensor (ECS) on shape memory polymer (SMP) for aqueous lead detection. This technology has shown promising performance in the application of electrochemical sensing (lead (II) detection) due to increased effective electrode surface area (7.25 mm^2 ± 0.15 mm^2) despite miniaturizing lateral surface area (4.19 mm^2). The design, fabrication processes, optimization including bismuth functionalization, evaluation, uncertainty analysis, and cost analysis of the novel SMP based inkjet printed Au plated sensor have been delineated in this manuscript in detail. Sensor characterization, optimization, and evaluation have been performed using electrochemical analysis i.e., cyclic voltammetry (CV), square wave anodic stripping voltammetry (SWASV), and electrochemical impedance spectroscopy (EIS). The fabricated ECS consists of Au working electrode (WE), Au counter electrode (CE), and silver chloride (AgCl) reference electrode (RE). Immersion Au plating (24K) has been applied on inkjet printed silver (Ag) electrodes to fabricate Au WE and CE. Chlorination using sodium hypochlorite solution has been utilized to fabricate AgCl reference electrode. Bismuth functionalization has been performed in two different ways i.e., ex situ - a full range of CV has been conducted to bismuth plate the Au electrode with the solution of 400 µg/L bismuth salt and in situ – CV and SWASV have been performed with lead contaminated aqueous solution diluted with 200 µg/L bismuth salt. The limit of detection of the fabricated inkjet printed ECSs are 0.76 µg/dL – Au WE, 0.64 µg/dL – bismuth plated WE, and 1.4 µg/dL – Au WE with lead contaminated aqueous solution diluted with 200 µg/L bismuth salt. EIS measurement for the fabricated ECSs (64.07±7.19 Ω) has also been conducted using phosphate buffer saline (PBS; pH 7.4) to investigate the reproducibility of the fabricated ECSs.

Language

en

Provenance

Recieved from ProQuest

File Size

145 p.

File Format

application/pdf

Rights Holder

Annatoma Arif

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