Detecting and identifying single molecules are the ultimate goal of analytic sensitivity. Single molecule detection by surface-enhanced Raman scattering (SM-SERS) depends predominantly on SERS-active metal substrates that are usually colloidal silver fractal clusters. However, the high chemical reactivity of silver and the low reproducibility of its complicated synthesis with fractal clusters h...

In this paper we report on the engineering of repeatable surface enhanced Raman scattering (SERS) optical fiber sensor devices (optrodes), as realized through nanosphere lithography. The Lab-on-Fiber SERS optrode consists of polystyrene nanospheres in a close-packed arrays configuration covered by a thin film of gold on the optical fiber tip. The SERS surfaces were fabricated by using a nanosph...

The dominant molecular species contributing to the surface-enhanced Raman spectroscopy (SERS) spectra of bacteria excited at 785 nm are the metabolites of purine degradation: adenine, hypoxanthine, xanthine, guanine, uric acid, and adenosine monophosphate. These molecules result from the starvation response of the bacterial cells in pure water washes following enrichment from nutrient-rich envi...

The purpose of this work is to develop a high-performance surface-enhanced Raman scattering (SERS) substrate with high light harvesting and SERS emitting efficiencies based on the principle of a plasmonic nano-antenna. A prism/Ag nanowell array was designed and constructed based on the Kretschmann configuration. Almost 100% of the incident light can be absorbed at the resonance angle. A strong ...

Surface enhanced Raman spectroscopy (SERS) has been widely investigated as an effective technique for low-concentration bio-chemical molecules detection. A rapid two-step approach to fabricate SERS substrates with high controllability in ambient air is developed. Dynamic laser ablation directly creates microgroove on the Si substrate. Meanwhile, nanoparticles are synthesized via the nucleation ...

A microfluidic device with integrated silver nanoparticles (AgNPs) was fabricated via in situ galvanic replacement of a pre-patterned copper substrate in a microfluidic channel. The integrated microfluidic device with AgNPs serves as a highly active Raman substrate which can be applied for in-channel surface-enhanced Raman scattering (SERS). Preparation of the SERS active substrate and subseque...

Chemical sensing on the nanoscale has been breaking new ground since the discovery of surface enhanced Raman scattering (SERS). For nanoparticles, controlled particle aggregation is necessary to achieve the largest SERS enhancements. Therefore, aggregating agents such as salts or linker molecules are used in conjunction with chemically sensitive reporters in order to develop robust environmenta...

Graphene oxide (GO) is an emerging material for surface-enhanced Raman scattering (SERS) due to its strong chemical enhancement. Studying the SERS performance of plasmonic nanoparticle/GO hybrid materials at the single particle level is crucial for direct probing of the chemical effect of GO on plasmonic nanoparticles. In this work, we integrate GO and shape-controlled Ag nanoparticles to creat...

The first observations of the Raman spectra of pyridine on roughened silver were made in 19741; however, at this time the authors did not recognize that these spectra were due to any unusual, enhanced, or new phenomena. Since its discovery in 19772, interest in and the use of surface enhanced Raman spectroscopy (SERS) has grown exponentially (Fig. 1). The SERS field has dramatically progressed ...

We demonstrate label-free detection of lipid vesicles and polystyrene beads freely diffusing in aqueous solution using surface enhanced Raman scattering (SERS). The signals observed enable real-time identification and monitoring of individual particles interacting with the SERS substrate. SERS is demonstrated as a label-free method capable of monitoring transient species in solution on the mill...