My research program is focused on two main areas: The first is research that involves several aspects of electrochemistry. These include the applications of electroanalytical chemistry utilizing low-cost carbon electrodes. The second involves research that determines environmental pollutants in soil and water. The focus of the research is the determination of heavy metals using atomic absorption spectroscopy and voltammetric methods. More details of my research program are given below.
a) Preparation and Characterization of Thin Films on Carbon Electrodes
The first component of my research program is focused on the modification and use of carbon electrodes. The aim is to improve the efficiency of the carbon electrodes by changing their surface properties. The carbon electrodes are modified by attaching thin films on the surface. This is done by the electrochemical reduction of diazonium salts, which leads to covalent attachment of a thin film onto the carbon surface. Electrochemical blocking studies with cyclic voltammetry are used to study the properties of the modified carbon electrodes.
b) Development and Applications of Electroanalytical Chemistry Techniques
This research area is focused on utilizing electroanalytical methods for practical applications. The main objective is to use electrochemical techniques in the determination of a variety of analytes in diverse samples. One of our main focus areas is food chemistry. An example is the determination of antioxidants in fruit and vegetable samples.
Another goal of the research program is to develop low-cost disposable carbon electrodes for use in electrochemical sensors. We also use chemical-based assays for the determination of antioxidants as a complimentary technique to determine the amounts of antioxidants in foods.
c) Determination of Heavy Metals in Soil and Water Samples Using Atomic Absorption Spectroscopy
This research program focuses on the determination of heavy metals in soil and water samples. The amount of heavy metals is determined using both flame-based atomic absorption and graphite furnace spectroscopy. This research area is of interest to both chemistry and environmental chemistry majors.
- Kariuki, J.; Ervin, E.; Olafson, C. Development of a novel, low-cost, disposable wooden pencil graphite electrode for use in the determination of antioxidants and other biological compounds (Invited). Sensors. 2015,15, 18887-18900.
- Ervin, M. E.; Kariuki, J. K. Effect of Extraction Method on Antioxidant Determination in Produce by Differential Pulse Voltammetry. Int. J. Electrochem. Sci. 2014, 9, 6235-6245.
- Ervin, M. E.; Adams, B. T.; Snyman, N.; Phenix, C. P.; Kariuki, J. K.; Rempel, B. P. Carbohydrate-Modified Electrode Surfaces Sensitive to β-Glucosidase Enzyme Activity. Int. J. Electrochem. Sci. 2014, 9, 6043-6048.
- Merichel, M.; Kariuki, J.; Turner, C. Quantification of Individual Phenolic Compounds’ Contribution to Antioxidant Capacity in Apple: A Novel Analytical Tool Based on Liquid Chromatography with Diode Array, Electrochemical, and Charged Aerosol Detection. J. Agric. Food Chem. 2014, 62 (2), 409–418.
- Kariuki, J. K. An Electrochemical and Spectroscopic Characterization of Pencil Graphite Electrodes. J. Electrochem. Soc. 2012, 159(9), H747-H751.
- Esch, J. R.; Friend, J. R.; Kariuki, J. K. Determination of the Vitamin C Content of Conventionally and Organically Grown Fruits by Cyclic Voltammetry. Int. J. Electrochem. Sci. 2010, 5, 1464-1474.
- King, D.; Friend, J.; Kariuki, J. K. Measuring Vitamin C Content of Commercial Orange Juice Using a Pencil Lead Electrode. J. Chem. Educ. 2010, 87(5), 507-509.
- Kanda, V.; Kariuki, J. K.; Harrison, D. J.; McDermott, M. T. Label-Free Reading of Microarray-Based Immunoassays with Surface Plasmon Resonance Imaging. Anal. Chem. 2004, 76(24), 7257-7262.
- Furdui, V. I.; Kariuki, J. K.; Harrison, D. J. Microfabricated Electrolysis Pump System for Isolating Rare Cells in Blood. J. Micromech. Microeng. 2003, 13, S164-S170.
- Kariuki, J. K.; McDermott, M. T. Formation of Multilayers on Glassy Carbon. Langmuir, 2001, 17, 5947-5951.
- Goh, A. Y. L.; Kariuki, J. K.; Skelhorne, A. W.; Bhattacharyya, A.; McDermott, M. T.; Forest, T. W.; Steadman, G. Preliminary Results on the Effect of Methanol-Based Fuels on the Tensile Properties of FRP Micro-Specimens. Advanced Composites Letters, 2001, 10(4), 155-169.
- Kariuki, J. K.; McDermott, M. T. Nucleation and Growth of Functionalized Aryl Films on Graphite Electrodes. Langmuir, 1999, 15, 6534-6540.
- Olafson, C.; Kariuki J. (2016). Analyzing the Effect of Brewing Method on Antioxidant Content of Coffee Using Activated Pencil Graphite Electrodes. 30th Western Canadian Undergraduate Chemistry Conference, Winnipeg, Canada.
- Kariuki, J.; Olafson, C.; Ervin, E. (2016). Utilization of a Low-Cost Pencil Graphite Electrode for Electroanalytical Analysis. 99th Canadian Chemistry Conference and Exhibition, Halifax, Canada.
- Kariuki, J.; Rempel, B.; McGinitie, E. (2016). Colour in Our World: Using Colour Changes to Visualize Chemical Reactions. University of Alberta, Augustana Campus, Faculty Talk Series, Camrose, Canada.
- Marynowski, C.; Kariuki, J. (2015). Utilizing Chemistry Demonstrations to Enhance Student Learning with. Our Lady of Mount Pleasant Catholic School Chemistry Demonstrations Presentation, Camrose, Canada.
- Kariuki, J.; Ervin, E.; Olafson, C. (2015). Low Cost Electrochemistry: Current and Future Applications. International Symposium on Chemical Innovation, Education and Commercialization, Canmore, Canada.
- Kariuki, J.; Ervin, E.; Olafson, C. (2015). Voltammetric Determination of Antioxidants with a Low-Cost Pencil Graphite Electrode. 98th Canadian Chemistry Conference and Exhibition, Ottawa, Canada.
- Kariuki, J.; Olafson, C.; Ervin, E.; Duan, J.; Marsden, N. (2015). Chemistry That You Can See: Chemistry Demonstrations. Junior High Grade 9 Students, Camrose, Canada.
- Kariuki, J.; Rempel, B. (2014). Fun with Chemistry: Chemistry Demonstrations. Augustana Campus Science Olympics, Camrose, Canada.
- Ervin, E.; Kariuki, J. (2014). Using Pencil Graphite Electrodes for the Determination of Antioxidants in Fruits and Vegetables. Student Academic Conference, Augustana Campus, University of Alberta, Camrose, Canada.