Surface enhanced Raman spectroscopy (SERS) requires the analyte molecule to be close to the plasmonic surface in order to generate SERS enhancement. This limitation restricts the practical application of SERS to molecules that possess functional groups that interact strongly with gold or silver surfaces. Moreover, the identification of target analytes in a complex sample matrix is made even more difficult when interferents compete with the target for binding to the plasmonic surface, resulting in overlapping spectral signatures. In this work, we report a strategy to functionalize inkjet printed P-SERS substrates by strategically placing supramolecular structures (such as nucleic acid aptamers) onto the gold nanoparticles. This promotes the selective interaction of target molecules with the plasmonic surface, leading to improved sensor performance.
We report the application of paper SERS substrates for the detection of trace quantities of multiple analytes in a complex sample in the form of paper chromatography. Paper chromatography facilitates the separation of different analytes from a complex sample into distinct sections in the chromatogram, which can then be uniquely identified using SERS. As an example, the separation and quantitative detection of heroin in a highly fluorescent mixture is demonstrated. Paper SERS chromatography has obvious applications, including law enforcement, food safety, and border protection, and facilitates the rapid detection of chemical and biological threats at the point of sample.
We report the development of a novel, low-cost surface enhanced Raman spectroscopy (SERS) substrate that is
fabricated by ink-jet-printing silver nanostructures into cellulose paper. Analysis of a liquid sample is performed by
spotting a 1 microliter droplet onto the printed SERS substrate. The droplet is contained within a small area of the SERS
substrate by ink-jet-printing hydrophobic barriers to define microfluidic boundaries. Using Rhodamine 6G as the
analyte, we are able to measure a strong SERS fingerprint signal when only 10 femtomoles of analyte are applied to the
Video applications over the Internet are getting increasingly popular because of the explosive growth of the Internet. However, video packets loss due to network congestions can degrade the video quality substantially. In this paper, we propose a transmission scheme for Motion-JPEG2000 video sequences with an active networking approach. Our scheme utilizes the progression modes in Motion-JPEG2000. It can be implemented in an active network environment efficiently. Our simulation shows that the proposed scheme gracefully adapts to network congestion and improves the quality of video transmission in congested IP networks.
The new ISO/ITU-T standard for still image coding, JPEG2000, has been shown to provide superior coding efficiency to the previous standard, JPEG. Because of the superb performance of JPEG2000, it is reasonable to argue that Motion-JPEG2000, the corresponding moving picture coding standard of JPEG2000, has equally outstanding performance. However, there has not been a sufficient performance evaluation of Motion-JPEG2000. To this end, we have studied the potential of Motion-JPEG2000 for video processing. Our experiments show that Motion-JPEG2000 provides high compression performance, strong error resilience, and good perceptual image quality. Together with a rich set of features inherited from JPEG2000, Motion-JPEG2000 has advantages as a coding standard for video processing in many applications.