Tualatin, Oregon, United States
Personal website: https://evelyn-zhang4.github.io/
Electronic-based sensor integrated with digital microfluidics (DMF) for immunoassay detection • Conceptualized and established an integrated DMF device configured with electrochemical biosensor to achieve the extraction and detection of circulating biomarkers in a rapid and automated manner • Created and implemented experimental strategies to enhance the functionality and modification of sensor surfaces by forming a self-assembled monolayer (SAM) at the gold electrode surface, facilitating the integration of bioassays for improved sensor performance • Optimized the design formats of interdigitated electrode (IDE) assay for 3X enhanced sensitivity of EIS detection by analyzing their electric field distributions using FEA via COMSOL multiphysics • Innovated a dynamic incubation method of cell-based immunoassay on integrated DMF device, achieving highly sensitive quantification of human peripheral blood mononuclear cell down to 1,000 cells per mL • Developed an electrochemical biosensor that functionalizes a reduced graphene oxide-based conductive 3D matrix structure on the sensor surface and integrates it onto a DMF device to achieve exceptional sensitivity for the detection of soluble PD-L1 protein as low as 1 pg/mL • Developed a DMF system incorporating magnetic immunoassay to directly isolate EVs from biofluids in a rapid and programmable manner with reduced sample and reagent consumption • Optimized the durability and stability of DMF devices, by adjusting the tetronic surfactant for exceptional antifouling performance, optimizing the thickness of the Parylene C dielectric and hydrophobic layers, and fine-tuning the droplet operation voltage and frequency • Phenotyped an electrochemcial biosensor integrated on DMF devices to quantify the PD-L1 expression levels on extracted EVs in series dilution rates (10-10,000) with good linearity (R² = 0.9176)
Sequence-specific detection of nucleic acids utilizing nanopore-based sensor}} • Developed a high-fidelity numerical model of solid-state nanopore in COMSOL multiphysics to study the fluid flow performance and provided a validation on electroosmosis-based detection principle with nanopore • Created mathematic models for the analysis of electrokinetics (electrophoresis, electroosmosis and dielectrophoresis) of aqueous solutions and electrokinetic particle separation phenomena • Optimized the nucleic acid hybridization conditions including salt condition and temperature for a higher stringency between peptide nucleic acid (PNA) and microRNA/double-stranded DNA • Phenotyped an innovative nanopore-based sensor with borosilicate beads as substrate to detect microRNAs at fM range with 97.6\% detection accuracy • Designed operational amplifier circuits to amplify sub-ampere signals; logged current data using a data acquisition model (USB 6361) written in LabVIEW program; and processed the signal filtration and fitting using MATLAB Characterization of exosomes by an electrical impedance spectroscopy (EIS)-based system • Conceptualized and developed an EIS-based measurement system to characterize EVs derived from different cellular origins based on the dielectric properties by sweeping the immobilized EVs across a frequency range from kHz to MHz • Established an equivalent circuit model based on the Foster and Schwan circuit model to simulate the dielectric properties of vesicles in suspension as a function of frequency based on Maxwell’s mixing theory • Implemented a Python code (involving Pandas, numpy, matplotlib, openpyxl, wxPython, and cx-Freeze) to analyze the high-throughput impedance data • Implemented the impedance-based sensor with fundamental microfabrication technologies including photolithography, wet etching, reactive-ion etching, and E-beam evaporation etc.
• Bio-microfluidic Systems, EECE6078: Designed and lectured 6 COMSOL tutorials: passive/electroosmotic micromixers; micropump; dielectrophoretic separation; nanopore sensor • Biomedical Microsystems, EECE6007: Assisted and graded >100 students with the coursework of the class; Held office hours