| Posted: Nov 23, 2015 |
Smart sensor detects single molecule in chemical compounds(Nanowerk News) Australian and Italian researchers have developed a smart sensor that can detect single molecules in chemical and biological compounds – a highly valued function in medicine, security and defence (Nature Communications, "Reversible gating of smart plasmonic molecular traps using thermoresponsive polymers for single-molecule detection"). |
| The researchers from the University of New South Wales, Swinburne University of Technology, Monash University and the University of Parma in Italy used a chemical and biochemical sensing technique called surface-enhanced Raman spectroscopy (SERS), which is used to understand more about the make-up of materials. |
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| They were able to greatly amplify the technique’s performance by taking advantage of metal nanostructures, which help generate ‘hotspots’ in close proximity to the metal surfaces. |
| The sensor was created using gold nanoparticles which self-assemble onto a gold- and silica-coated silicon base. This approach means the nanoparticles find the perfect spacing to achieve lots of uniformly distributed hotspots on the surface. |
| The hotspots also used a heat responsive polymer which acted as a gate to trap molecules, but importantly also allow them to be released down the track. |
| “The sensor shows not only a good SERS reproducibility but also the ability to repetitively catch and release molecules for single-molecular sensing,” postdoctoral fellow at Swinburne's Centre for Micro-Photonics, Dr Lorenzo Rosa, said. |
| “This reversible trapping process makes it possible to detect an abundance of analytes in one measurement, but also to reuse the SERS substrate multiple times.” |
| The technique used in this work has various applications for other measurement and detection systems sensitive to humidity, pH and light. |
| Source: Swinburne University |
