Blog Global Health Center

Ultrasensitive and minimally invasive biodiagnostics

Written by Devin Diggs, BS candidate in Neuroscience & Behavior at the University of Notre Dame and participant in the 2021 Institute for Public Health Summer Research Program

In an afternoon seminar, Associate Professor, Srikanth Singamaneni, PhD, School of Engineering & Applied Sciences, spoke to the 2021 cohort of the Institute for Public Health Summer Research Program, Public and Global Health Track. With research projects spanning from electrical and computer engineering to neuromodulation, Dr. Signamaneni encouraged students to venture into new fields and not let lack of experience discourage us from pursuing our interests.

Devin Diggs at Kakum National Park in Ghana

Dr. Singamaneni’s current research focuses on novel ultrasensitive and minimally invasive biodiagnostic techniques. Conventional molecular diagnostics are considered 1st wave: a sample is drawn from the patient, and that sample is then transported to the lab for analysis. His research aims to implement 2nd and 3rd wave diagnostic strategies that involve performing analysis at the site of the sample and having patients wear the analysis device, respectively.

The Singamaneni research group is interested in methods of collecting and analyzing interstitial fluid (ISF), the fluid present in between cells in a given tissue. ISF is a rich source of biomarkers—more than 99% proteins present in plasma are also present in ISF. Despite the rich source of biomarkers, current extraction methods using microneedles are not able to isolate a sufficient amount of fluid for conventional methods of analysis. Dr. Sigamaneni’s plasmonic biosensors, in conjunction with the microneedle technology, are able to overcome this limitation through their ultrasensitivity.

Microneedle patch from Srikanth Singamaneni’s lab with fluorescent labels identifying biomarkers of interest. Photo: Washington University in St. Louis School of Engineering News

Plasmonic biosensors, also known as plasmonic fluors, are labels that enhance the signals of conventional analysis methods of FLISA (fluorescence-linked immunosorbent assay) and ELISA (enzyme-linked immunosorbent assay). Each plasmonic fluor is 7000 times brighter than the corresponding standard dye. While normal ELISA assays can take 280 minutes, using this new plasmonic fluor technology can process the same results in 20 minutes. The enhanced sensitivity and faster analysis make this new technology especially well-suited for limited-resource environments.

While still in the early stages, the goal of this research is to develop this diagnostic technique that would allow for patients to administer the microneedle themselves and perform the simple analysis procedure. This technology would not require the refrigeration of samples, a centralized lab facility for analysis, or long turnaround times between sample collection and results. These are all current obstacles for biodiagnostics in low-resource settings, highlighting how this novel technology could pave the way for substantial public health benefits in developing areas. The plasmonic biosensors provide rapid diagnostics that could translate to faster treatments to those infected with disease, where prompt medical attention is crucial for best outcomes.

Dr. Singamaneni’s experience working in biodiagnostics showed us how advances in technology can be harnessed to improve the health of communities. Social factors of health and nanotechnology can be seemingly disparate, but this seminar revealed how they are more intertwined than meets the eye.