@ARTICLE\{IMM2013-06819, author = "J. Yang and M. Palla and F. G. Bosco and T. Rindzevicius and T. S. Alstr{\o}m and M. S. Schmidt and A. Boisen and J. Ju and Q. Lin", title = "Surface-Enhanced Raman Spectroscopy Based Quantitative Bioassay on Aptamer-Functionalized Nanopillars Using Large-Area Raman Mapping", year = "2013", pages = "5350-5359", journal = "{ACS} nano", volume = "7", editor = "", number = "6", publisher = "", url = "http://www2.compute.dtu.dk/pubdb/pubs/6819-full.html", abstract = "Surface-enhanced Raman spectroscopy (SERS) has been used in a variety of biological applications due to its high sensitivity and specificity. Here, we report a {SERS-}based biosensing approach for quantitative detection of biomolecules. A {SERS} substrate bearing gold-decorated silicon nanopillars is functionalized with aptamers for sensitive and specific detection of target molecules. In this study, {TAMRA-}labeled vasopressin molecules in the picomolar regime (1 pM to 1 nM) are specifically captured by aptamers on the nanostructured {SERS} substrate and monitored by using an automated {SERS} signal mapping technique. From the experimental results, we show concentration-dependent {SERS} responses in the picomolar range by integrating {SERS} signal intensities over a scanning area. It is also noted that our signal mapping approach significantly improves statistical reproducibility and accounts for spot-to-spot variation in conventional {SERS} quantification. Furthermore, we have developed an analytical model capable of predicting experimental intensity distributions on the substrates for reliable quantification of biomolecules. Lastly, we have calculated the minimum needed area of Raman mapping for efficient and reliable analysis of each measurement. Combining our {SERS} mapping analysis with an aptamer-functionalized nanopillar substrate is found to be extremely efficient for detection of low-abundance biomolecules.", isbn_issn = "10.1021/nn401199k" }