Metallic particles shine a light on biomedical procedures

Researchers have found that metal particles can be used in biomedical and biotechnology procedures by boosting weak or non-fluorescent molecules up to 2000 thousands times better.

University of Maryland Biotechnology Institute (UMBI) and the University of Maryland School of Medicine (UMSM) researchers report that using metals with new Radiative Decay Engineering (RDE) technology results in highly useful emissions from non-fluorescent molecules such as DNA.

If widely adapted, the innovation would have profound implications for the use of fluorescence in basic research and technology, they report. High sensitivity detection of DNA is essential for advancing genomics.

‘It is a highly unusual effect and will improve DNA sequencing and analysis, as well as in different kinds of immunoassaid,’ said Joseph Lakowicz, who directs the National Centre for Fluorescence Spectroscopy in the US.

Fluorescence spectroscopy is already employed as a research tool, having largely enabled current advances in medical diagnostics, DNA sequencing and genomics.

‘In spectroscopy, we usually have no significant control over the radiative rate,’ said Lakowicz

However, he reports that RDE, by modifying a rate of how intrinsically weak fluorescent molecules radiate, will enhance DNA hybridisation, drug discovery and fluorescence immunoassaid. The use of metal particles could greatly increase the sensitivity of the assaid, he said.

‘By describing our concept of Radiative Decay Engineering and its implications, we hope to spark interdisciplinary work between physicists, engineers, chemists and biologists to design and construct appropriate nanoscale or mesoscale devices and make the complex spectral observations needed to stimulate the field,’ said Lakowicz.

The completion of the human genome sequence is driving development of a wide variety of new approaches to DNA analysis, such as DNA arrays or gene chips, PCR-based assaid and hybridisation assaid.

The researchers said metal-enhanced methods might now be used to probe longer-range structures in DNA, RNA or ribosomes.

‘While the human genome and genomes of other organisms have been sequenced, there is still a need for faster, cheaper and more sensitive DNA sequences,’ concluded Lakowicz.