My group’s current research efforts are focusing on the following six projects.

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1. Development of Robust Synthetic Nanopore Sensors for Portable/Fieldable Applications

2. Nanopore Protein Sequencing

3. Development of New Porous Membranes as Innovative Separators in Lithium-ion Batteries

4. Fieldable Nanopore Platform for Rapid & Sensitive Detection and Decontamination of Uranium, Plutonium, and other Radioactive Elements

5. Detection of Biodefense and Emerging Infectious Diseases 

6. Development of Next-Generation Fluorescent Sensing Platforms for Biomarker Detection

The project regarding development of robust synthetic nanopore sensors for portable applications is briefly described below.

Nanopore stochastic sensing has shown a great potential as a versatile tool for a wide variety of applications. However, the various applications of the nanopores reported so far were mainly achieved using protein ion channels. The high sensitivity and selectivity of these biological nanopores are accomplished based on modification of the nanopore interior to introduce a variety of new functions at specific positions. Although these sensors can be used as effective tools, e.g., for the early detection and diagnosis of infectious diseases and human cancers in a laboratory environment, they are not suitable as portable devices for point-of-care (POC) diagnostics due to the fragility of the biological membrane (i.e., phospholipid bilayers) used in such a sensing platform.  Development of artificial nanopores in robust solid-state substrates offers a great potential as portable/fieldable stochastic sensors.  These artificial pores have many advantages over the biological pores.  For example, they can have flexible pore diameters and lengths, function in a variety of extreme conditions (e.g., voltage, temperature, and solvent variations), and be used repetitively. Unfortunately, the poor resolution & sensitivity of the current synthetic nanopore sensing technique limits its practical applications. This limitation will be addressed in this project.

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i) Polymeric nanopores. Thus far, there were rare reports of utilizing polymeric nanopores as single-molecule stochastic sensing elements for sensor applications. Building on our recently pioneered functionalized polyethylene terephthalate (PET) nanopore stochastic sensing technology for protein detection and characterization, we will systematically examine the effects of various factors on the interaction between proteins and PET nanopores, so that the relationships between the kinetic & thermodynamic properties of proteins inside PET nanopores and the pore diameters, pore inner surface functions and physical conditions could be established. Findings discovered in this work will benefit our understanding of molecular transport in PET nanopores, which may provide novel insight into more rigorous design of PET nanopore stochastic sensors, thus leading to a significant advance in nanopore technology. This project has recently been funded by NSF (CHE-2203763, 08/01/2022 – 07/31/2025).

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ii) Si3N4 nanopores. In another study, we are developing a portable Si3N4 nanopore-based device for protein detection. As a model system, our initial investigation will focus on detection of sepsis protein biomarkers. Sepsis is a global healthcare problem with a large number of incidence and a high risk of deaths due to the aging of the population, the widespread use of antibiotics, and the increase of drug-resistant bacteria. The latest epidemiological study showed that, in 2017, there were 48.9 million sepsis patients and 11 million sepsis-related deaths worldwide, which was equivalent to 19.7% of total deaths throughout the year. Sepsis is characterized by whole body inflammation as a result of a dysregulated host immune response to microbial infection, which leads to the syndrome of multiple organ dysfunction. At present, there is no specific treatment for sepsis; its management basically focuses on containing the infection through source control and antibiotics plus organ function support. It has been reported that the potential survival rate of sepsis falls dramatically up to 7.6% per hour without effective antibiotic treatment. Therefore, early diagnosis of sepsis is required urgently to prevent the development of the disease and to ensure rapid administration of appropriate antibiotic treatment. Most recently, our sepsis early diagnosis project has been selected by NIH for funding (Award Pending, 1R01GM147247-01, 09/01/2022 – 08/31/2026.

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iii) Early detection, diagnosis and prognosis of human diseases. Building on the new findings discovered in the above polymeric nanopore and Si3N4 nanopore projects, we will develop a portable/fieldable solid-state nanopore device, which is able to detect a series of protein, nucleic acid and protease biomarkers for cancer, cardiovascular diseases, infectious diseases, etc. The long-term goal of this project is to develop a point-of-care (POC) device for use in either a clinician’s office, hospital or at home.