MIE’s Jinglei Ping and His Students Develop Pioneering Method for Detecting Protein Concentrations in Assays

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Jinglei Ping

Many studies in biology and medicine – including those involved in clinical diagnostics, many therapeutics, and large-scale studies of proteins – rely on detecting protein concentrations in samples. Such studies often depend on detecting minute protein concentrations and are thus constrained by the protein-detection limit of the sensors used. Faced with this limitation, researchers are forced to employ more-expensive detectors or more-complicated assays. In response to this challenge, a research team led by Jinglei Ping – an assistant professor in the UMass Amherst Mechanical and Industrial Engineering (MIE) Department who is also affiliated with the Institute for Applied Life Sciences – has developed a groundbreaking method for concentrating proteins in such samples, amplifying the detection limit in their protein analysis, and measuring these protein concentrations less expensively and more effectively.

Ping’s revolutionary method employs an inexpensive isoelectric focusing technique, which can detect proteins at concentrations four times lower, and therefore four times more effective, than is currently possible. This work is supported by Ping’s Maximizing Investigators' Research Award from National Institutes of Health, National Institute of General Medical Sciences.

The team described its new technique in the March 4 issue of Applied Physics Letters (https://doi.org/10.1063/5.0190380) in a paper authored by Ping and four MIE Ph.D. researchers from his lab: Xiao Fan, Xiaoyu Zhang, Huilu Bao, and Xin Zhang. The same paper was later selected as a “Featured Article” by Applied Physics Letters and then attracted notice on the website of Scilight, which “showcases the most interesting research across the physical sciences published in AIP Publishing Journals.” See https://pubs.aip.org/aip/sci/article/2024/10/101101/3268266/Isoelectric-focusing-technique-enables-protein.

As a consequence of the limitations mentioned in the first paragraph and the complications they trigger, augmenting the detection limit in protein analysis is necessary for a wide range of biomedical applications. 

In the Applied Physics Letters paper, Ping’s team describes a method for doing just that: “Our approach offers a simple, yet highly effective, ultra-low-power, all-electronic solution for substantially improving protein-analysis detection limits for diverse applications, including healthcare, clinical diagnostics, and therapeutics.”

 As the Scilight feature explains, “The device consists of two concentric rings overlaid on the desired sample, with a voltage applied between them. This voltage produces a current, and therefore a pH gradient, across the rings that pulls proteins to its center.”

According to Ping, “Since we can control the pH within that range, the proteins can be concentrated through a technique called isoelectric focusing. Proteins will take on a charge and move to the electrode with the opposite polarity until they are charge-neutral. The central region is where those proteins stop moving and become concentrated.”

In tests, as the Scilight feature notes, “The device demonstrated not only an ability to concentrate proteins, but also an ability to lower their random motion, resulting in less measurement noise. The authors are looking forward to testing the capabilities of this technique in their own research.”

As Ping explains, “We are going to integrate this technique with cell systems, such as cancer cells, to see how we can use it to deliver proteins. We are also interested in integrating this technique into a lab-chip device for detection of proteins with higher sensitivity.”

In general, the goal of Ping’s lab (Ping Lab | Nano/Bio Interfaces & Applications) is “to determine the fundamental principles governing applications of nanomaterials and nanomaterial-based device structures in biotechnology, healthcare, environmental monitoring, and so on.” (April 2024)