In a significant breakthrough, scientists have successfully detected the X-ray signal of a single atom for the first time. The findings of the research, led by Argonne National Laboratory scientist Saw Wai Hla, have the potential to revolutionize fields such as quantum information, nanotechnology, and environmental and medical science research, according to a study published in the scientific journal Nature on Wednesday.
Traditionally, X-rays could detect masses as small as an attogram, equivalent to about 10,000 atoms. However, scientists have long sought a method to identify even smaller masses.
In their study, Hla and his team utilized a purpose-built synchrotron X-ray instrument at the XTIP beamline of the Advanced Photon Source and the Center for Nanoscale Materials at the Argonne laboratory.
“While atoms can be routinely imaged with scanning probe microscopes, the lack of X-ray detection limits our ability to identify their composition,” explained Hla, a physics professor at Ohio University. “With our new method, we can now detect the precise type of individual atoms, one at a time, while simultaneously measuring their chemical state.”
Hla continued, “This breakthrough allows us to trace materials down to the ultimate limit of just one atom. Its impact will be significant in environmental and medical sciences, and may even lead to groundbreaking discoveries that can greatly benefit humanity. This discovery will transform the world.”
To test their technique, the researchers selected an iron atom and a terbium atom, embedding them in their respective molecular hosts.
In order to detect the X-ray signal of a single atom, they enhanced conventional X-ray detectors with a specialized detector made of a sharp metal tip positioned extremely close to the sample, capable of collecting X-ray excited electrons. This technique is known as synchrotron X-ray scanning tunneling microscopy or SX-STM.
Hla has spent the past 12 years refining the SX-STM method.
“The technique and concept employed in this study have broken new ground in X-ray science and nanoscale studies,” said Tolulope Michael Ajayi, the first author of the paper and a doctoral researcher. “Moreover, using X-rays to detect and characterize individual atoms could revolutionize research and give rise to new technologies in fields such as quantum information and the identification of trace elements in environmental and medical studies, among others. This achievement also paves the way for advanced materials science instrumentation.”
Collaborating with scientists from Ohio University and the Argonne laboratory, researchers from the University of Illinois-Chicago also contributed to the study.
The ability to identify individual atoms represents a major advancement in the use of X-rays, which have been employed across a wide range of applications, from medical imaging to airport security screenings, and even the remote examination of rock compositions on Mars.
（Source: UPI)
