Inkjet Printed Surface Enhanced Raman Spectroscopy Array on Cellulose Paper

摘要

A novel, ultra low-cost surface enhanced Raman spectroscopyn(SERS) substrate has been developed by modifyingnthe surface chemistry of cellulose paper and patterningnnanoparticle arrays, all with a consumer inkjet printer.nMicroanofabrication of SERS substrates for on-chipnchemical and biomolecular analysis has been undernintense investigation. However, the high cost of producingnthese substrates and the limited shelf life severely limitntheir use, especially for routine laboratory analysis andnfor point-of-sample analysis in the field. Paper-basednmicrofluidic biosensing systems have shown great potentialnas low-cost disposable analysis tools. In this work, thisnconcept is extended to SERS-based detection. Using anninexpensive consumer inkjet printer, cellulose papernsubstrates are modified to be hydrophobic in the sensingnregions. Synthesized silver nanoparticles are printed ontonthis hydrophobic paper substrate with microscale precisionnto form sensing arrays. The hydrophobic surfacenprevents the aqueous sample from spreading throughoutnthe paper and thus concentrates the analyte within thensensing region. A SERS fingerprint signal for Rhodaminen6G dye was observed for samples with as low as 10nfemtomoles of analyte in a total sample volume of 1 μL.nThis extraordinarily simple technique can be used tonconstruct SERS microarrays immediately before samplenanalysis, enabling ultra low-cost chemical and biomolecularndetection in the lab as well as in the field at the pointnof sample collection.