Single-Droplet/cell electrochemistry

biophysical electrochemistry

protein aggregation and condensation

antimicrobial susceptibility

Education

• Ph.D., University of Miami, Coral Gables, FL., 2000
• M.S., Universidad del Valle, Cali, Colombia, 1996
• B.S., Universidad del Tolima, Ibague, Colombia, 1989

Research Interests

Research in our lab focuses on developing electroanalytical methods to address various challenges in biomedicine and technology. Currently, we are investigating individual micrometer-size particles like cells (bacteria, yeast, etc.), microdroplets, and others, as they collide in real time with microscopic disk electrodes (~10 micron in diameter). Each particle impact generates a random and individual signal from which particle information is inferred. Our goal is to develop measurement procedures to relate particle’s electrochemical signal with its size, arrival velocity, and physicochemical mechanisms occurring inside and around the particle for various applications. For example, to discriminate live-dead bacterial cells in antibiotic discovery. In another research thrust, we seek to characterize electrochemically pathological aggregation of proteins, which is associated with neurodegenerative diseases like Alzheimer’s and Parkinson’s. Our goal here is to uncover mechanisms and regulators of protein aggregation to develop early diagnostic tests and new therapeutic hypotheses that can lead to disease treatments.

To complement electrochemistry, researchers in our lab employ other analytical methods along with software tools to model experimental data. In addition to PhD students and postdocs, we are interested in mentoring undergraduate students who wish to pursue graduate careers in chemistry.

Select Publications

Wu, L., Ramirez, A., Vo, I.D., Haglund, E., Alvarez, J.C. “Can Electroactive Tracer Molecules Reveal Viscoelastic Structure by Measuring Non-Fickian Diffusion”, Angew. Chem. Int. Ed. 2025, e202425114.

Tubbs, A., Ahmed, J. U., Christopher, J., Alvarez, J.C., “Savitzky-Golay Processing and Bidemensional Plotting of Current-Time Signals from Stochastic Blocking Electrochemistry to Analyze Mixtures of Rod-Shaped Bacteria,” Anal. Methods, 2024, 16, 6570-6576.

Lutkenhaus, J.A., Ahmed, J.U., Hasan, M., Prosser, D. C., Alvarez, J.C., “Average Collision Velocity of Single Yeast Cells during Electrochemically Induced Impacts”, Analyst, 2024, 149, 3214-3223.

Ahmed, J.U., Lutkenhaus, J.A., Tubbs, A., Nag, A., Christopher, J., and Alvarez, J.C.,
“Estimating Average Velocities of Particle Arrival Using the Time Duration of the Current Signal in Stochastic Blocking Electrochemistry”, Anal. Chem., 2022, 94, 16560-16569.

Ahmed, J.U., Lutkenhaus, J.A., Alam, M.S., Marshall, I., Paul, D.K., Alvarez, J.C., “Dynamics of Collisions and Adsorption in the Stochastic Electrochemistry of Emulsion Microdroplets”, Anal. Chem., 2021, 93, 7993-8001.

Awards

• National Science Foundation Career Award 2007
• Excellence in Scholarship Award, College of Humanities and Sciences, VCU, 2007
• Outstanding Graduate Student Award, University of Miami, 2000