Surface enhanced Raman scattering

The detection and identification of bacterial, protein, and chemical pathogens is extremely important. The detection of protein and chemical pathogens (also called targets) is currently most commonly done using fluorescence detection of target-receptor binding. Although very sensitive, fluorescence detection requires the attachment of a “label” to the target, which can lead to alterations in target-receptor interactions caused by conformational changes or steric hindrance. For these reasons, there is considerable effort to investigate alternatives to fluorescent detection. Label-free sensors detect the hybridization of an affinity complex using a variety of methods including optical, mechanical, and electrochemical techniques. Surface plasmon resonance sensing is one promising optical label-free technique. Another emerging optical detection technique measures Raman scattering spectra from the target biomolecules by exploiting huge scattering cross-section enhancements by roughened noble metal surfaces; commonly referred to as surface enhanced Raman scattering (SERS). Raman spectroscopy is important because it provides an optical fingerprint of chemicals and biomolecules as it represents the vibrational frequencies of molecular bonds. Therefore, this label-free optical sensing technique has the ability to quantify molecules attached to the sensing surface, which should improve the well known problem of non-specific binding in all solid-surface sensing systems. Additionally, it is desirable to have small, rapid assays that use small sample volumes and capable of detecting several compounds of species in parallel. This is significant because in many cases sample collection is limited, and sample processing also requires time. All of these factors point toward being able to detect multiple agents in parallel using small sample volumes. We are developing new SERS substrates with densely packed hot-spot electromagnetic enhancements on materials that are easily integrated into microfluidic platform.

Nanotextured surfaces (a) 2D nanopyramids and (b) 1D nanogrooves. Scale bar: 100 nm. SERS measurement of R6G in dH₂O on Au nanopyramid surfaces (solid) and flat gold surfaces (dotted) (c) 5 µM (inset: AFM image of Au coated surfaces) and (d) 100 nM (inset: R6G).

Contact information

Mingliang Jin and Dr. Edwin Carlen

BIOS Lab on a Chip Group

MESA+ Institute for Nanotechnology

University of Twente

E-mail: M.Jin@utwente.nl & E.T.Carlen@utwente.nl

	Home > ... > Nanosensing and Technology > Surface enhanced Raman scattering
Home News & Highlights People Vacancies Research Education & Assignments Publications Intranet Internal Links External links Movies Sitemap Search	Emerging research topics \| Cells on chips \| Electrochemical systems \| Micro- and nanofluidics \| Nanosensing and Technology Surface enhanced Raman scattering The detection and identification of bacterial, protein, and chemical pathogens is extremely important. The detection of protein and chemical pathogens (also called targets) is currently most commonly done using fluorescence detection of target-receptor binding. Although very sensitive, fluorescence detection requires the attachment of a “label” to the target, which can lead to alterations in target-receptor interactions caused by conformational changes or steric hindrance. For these reasons, there is considerable effort to investigate alternatives to fluorescent detection. Label-free sensors detect the hybridization of an affinity complex using a variety of methods including optical, mechanical, and electrochemical techniques. Surface plasmon resonance sensing is one promising optical label-free technique. Another emerging optical detection technique measures Raman scattering spectra from the target biomolecules by exploiting huge scattering cross-section enhancements by roughened noble metal surfaces; commonly referred to as surface enhanced Raman scattering (SERS). Raman spectroscopy is important because it provides an optical fingerprint of chemicals and biomolecules as it represents the vibrational frequencies of molecular bonds. Therefore, this label-free optical sensing technique has the ability to quantify molecules attached to the sensing surface, which should improve the well known problem of non-specific binding in all solid-surface sensing systems. Additionally, it is desirable to have small, rapid assays that use small sample volumes and capable of detecting several compounds of species in parallel. This is significant because in many cases sample collection is limited, and sample processing also requires time. All of these factors point toward being able to detect multiple agents in parallel using small sample volumes. We are developing new SERS substrates with densely packed hot-spot electromagnetic enhancements on materials that are easily integrated into microfluidic platform. Nanotextured surfaces (a) 2D nanopyramids and (b) 1D nanogrooves. Scale bar: 100 nm. SERS measurement of R6G in dH₂O on Au nanopyramid surfaces (solid) and flat gold surfaces (dotted) (c) 5 µM (inset: AFM image of Au coated surfaces) and (d) 100 nM (inset: R6G). Contact information Mingliang Jin and Dr. Edwin Carlen BIOS Lab on a Chip Group MESA+ Institute for Nanotechnology University of Twente E-mail: M.Jin@utwente.nl & E.T.Carlen@utwente.nl