The home heart attack detector provides results in minutes, not hours

A tiny chip with a unique surface can accurately detect the blood biomarkers of a heart attack within minutes, a fraction of the time needed with current methods, even when they are at very low concentrations. The researchers behind the device see it as a diagnostic tool for the home.

With any heart attack, time is of the essence. The faster the diagnosis is made, the faster blood flow is returned to the heart and the less damage is done, improving patient outcomes. But heart attacks are a delicate matter whose symptoms can vary from person to person.

Someone who presents to the emergency room with a suspected heart attack will undergo a series of standard blood tests, including tests for the enzyme creatine kinase and the protein troponin, biomarkers that indicate damage to the heart muscle. The problem is that it can take one to two hours for the results of these tests to arrive from a lab.

Now researchers at Johns Hopkins University (JHU) have advanced the development of a tiny chip that diagnoses a heart attack by detecting these important biomarkers in minutes rather than hours, even when they are present in very low concentrations. They recently published their study results.

“Heart attacks require immediate medical intervention to improve patient outcomes. While early diagnosis is crucial, it can also be very challenging – and nearly impossible outside of a clinical setting,” said Peng Zheng, a research fellow at JHU and the study’s lead author. “We were able to invent new technology that can quickly and accurately determine whether someone is having a heart attack.”

The key is the chip’s unique “metasurface.” First, a single layer of polystyrene beads is arranged in a hexagonal pattern on a quartz substrate. Thin layers of gold and silicon dioxide are alternately deposited on top, filling the gaps between the beads before the beads are removed. What remains are nanoscale, pyramid-like stacks of gold and silicon dioxide metaatoms.

The combination of metal (gold) and dielectric (silicon) enhances the chip’s electric and magnetic fields, thereby improving Raman spectroscopy’s ability to analyze the patient’s blood. Raman spectroscopy is a chemical analysis technique that provides detailed information about a substance by using light – a wide range of laser wavelengths – to interact with its chemical bonds.

The chip “detected” heart attack biomarkers within seconds, even if they were present at extremely low concentrations. It was sensitive enough to detect biomarkers before they were found with current tests or discovered much later in a heart attack.

“We’re talking about speed, we’re talking about accuracy and we’re talking about the ability to take measurements outside of a hospital,” said Ishan Barman, a bioengineer in JHU’s Department of Mechanical Engineering. “We hope this can be made into a handheld device like one in the future Star Trek Tricorder, where you have a drop of blood and then, voilà, in a few seconds you have the discovery.”

The researchers clearly believe that there will be a home heart attack detector in the future. The proof-of-concept device could also be adapted for testing for cancer and infectious diseases, the researchers say.

“There is huge commercial potential,” Barman said. “There is nothing that limits this platform technology.”

The study was published in the scientific journal Advanced science.

Source: Johns Hopkins University