No abstract

Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive vibrational spectroscopy technique enabling detection of multiple analytes at the molecular level in a nondestructive and rapid manner. In this work, we introduce a new approach to fabricate deep subwavelength-scaled (sub-100 nm) metallic nanohole arrays (quasi-3D metallic nanoholes) on flexible and highly efficient SERS substrates. Target structures have been fabricated using a two-step process consisting of (i) direct pattern transfer of spin-coated polymer films onto polydimethylsiloxane (PDMS) substrates by plasma etching with transferred anodic aluminum oxide masks, and (ii) producing SERS-active substrates by functionalization of the etched polymeric films followed by Au deposition. Such an all-dry, top-down lithographic approach enables on-demand patterning of SERS-active metallic nanoholes with high structural fidelity even onto flexible and stretchable substrates, thus making possible multiple sensing modes in a versatile fashion. For example, metallic nanoholes on flexible PDMS substrates are highly amenable to their integration with curved glass sticks, which can be used in optical fiber-integrated SERS systems. Au surfaces immobilized by probe DNA molecules show a selective enhancement of Raman scattering with Cy5-labeled complementary DNA (as compared to flat Au surfaces), demonstrating the potential of using the quasi-3D Au nanohole arrays for bio-sensing applications.

Major challenges of miniaturizing flow cytometry include obviating the need for bulky, expensive, and complex pump-based fluidic and laser-based optical systems while retaining the ability to detect target cells based on their unique surface receptors. We addressed these critical challenges by (i) using a viscous liquid additive to control flow rate passively, without external pumping equipment, and (ii) adopting an immunobead assay that can be quantified with a portable fluorescence cell counter based on a blue light-emitting diode. Such novel features enable pumpless microflow cytometry (pFC) analysis by simply dropping a sample solution onto the inlet reservoir of a disposable cell-counting chamber. With our pFC platform, we achieved reliable cell counting over a dynamic range of 9-298 cells/μL. We demonstrated the practical utility of the platform by identifying a type of cancer cell based on CD326, the epithelial cell adhesion molecule. This portable microflow cytometry platform can be applied generally to a range of cell types using immunobeads labeled with specific antibodies, thus making it valuable for cell-based and point-of-care diagnostics.

Since March in 2013, Inland Aquaculture Research Center, NFRDI has cultivated 1,000 wild swamp eel(Monopterus albus) for species conservation research. While cultivating, 100 fishes showed clinical sign that darkness color, mucus hypersecretion and anus rubor. Even some of them were died. Result of anatomical test, all 100 fishes were infected with intestinal parasite, acanthocephalan. So we were going to determine the case of acanthocephalans infection in swamp eel(Monopterus albus) as histopathologically. Acanthocephalan was founded in alimentary canal only. Parasite were confirmed 19 unit in individual fish, averagely. Heavy infected fishes were confirmed enterocleisis by acanthocephalans. Worms were attachment in submucosa layer of alimentary canal by invading proboscis. Characteristic symptoms were observed in stomach and intestine, including hyperemia in mucous epithelium, infiltration of eosinophills in submucosa layer, inflammation, parasitic granuloma. Some fishes showed vacuolization of gastricgland epithelium, necrosis of intestinal mucosa. Other organs, excluding alimentary canal, were not found lesion. The results of this study, the effect of the acanthocephalan infection on swamp eel(Monopterus albus) could find and it seems to be a big help in the future swamp eel(Monopterus albus) cultivation.