Nano-biological systems interfacing solid nano-structured solid surfaces with biological compounds such as oligonucleotides or proteins are highly regarded as enabling materials for biosensing and biocatalysis applications. In particular nanostructures of noble metals such as gold or silver, when exposed to light, exhibit a phenomenon known as surface plasmon resonance, resulting in a buildup of localized high-energy regions, or “hot-spots”. Energy of these hot-spots may be used in a variety of ways, such as for example inducing of reduction-oxidation responses in biological materials. Furthermore, plasmonic hot-spots are also known to enhance inelastic scattering of light by materials located nearby, promising multi-functional applications that combine photo-catalytic stimulation of materials with their ultrasensitive characterization in the same design. In this work we developed a nano-biological system interfacing plasmonic gold nanostructures with thiolated single-stranded DNA carrying an important reduction-oxidation indicator, methylthioninium chloride, also known as methylene blue. Using surface-enhanced Raman spectroscopy (SERS), we have demonstrated the detection of immobilized DNA-bound methylene blue in sub-monolayer quantities.
Journal: TechConnect Briefs
Volume: 3, Biotech, Biomaterials and Biomedical: TechConnect Briefs 2018
Published: May 13, 2018
Pages: 221 - 224
Industry sector: Sensors, MEMS, Electronics
Topics: Sensors - Chemical, Physical & Bio