Real-Time Glucose Sensing by Surface-Enhanced Raman Spectroscopy in Bovine Plasma Facilitated by a Mixed Decanethiol/Mercaptohexanol Partition Layer

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• 作者：Olga Lyandres ; Nilam C. Shah ; Chanda Ranjit Yonzon ; Joseph T. Walsh Jr. ; Matthew R. Glucksberg ; and Richard P. Van Duyne
• 刊名：Analytical Chemistry
• 出版年：2005
• 出版时间：October 1, 2005
• 年：2005
• 卷：77
• 期：19
• 页码：6134 - 6139
• 全文大小：343K
• 年卷期：v.77,no.19(October 1, 2005)
• ISSN：1520-6882

文摘

A new, mixed decanethiol (DT)/mercaptohexanol (MH)partition layer with dramatically improved properties hasbeen developed for glucose sensing by surface-enhancedRaman spectroscopy. This work represents significantprogress toward our long-term goal of a minimally invasive, continuous, reusable glucose sensor. The DT/MH-functionalized surface has greater temporal stability,demonstrates rapid, reversible partitioning and departitioning, and is simpler to control compared to the tri(ethylene glycol) monolayer used previously. The dataherein show that this DT/MH-functionalized surface isstable for at least 10 days in bovine plasma. Reversibilityis demonstrated by exposing the sensor alternately to 0and 100 mM aqueous glucose solutions (pH ~7). Thedifference spectra show that complete partitioning anddepartitioning occur. Furthermore, physiological levels ofglucose in two complex media were quantified usingmultivariate analysis. In the first system, the sensor isexposed to a solution consisting of water with 1 mMlactate and 2.5 mM urea. The root-mean-squared errorof prediction (RMSEP) is 92.17 mg/dL (5.12 mM) with87% of the validation points falling within the A and Brange of the Clarke error grid. In the second, morecomplex system, glucose is measured in the presence ofbovine plasma. The RMSEP is 83.16 mg/dL (4.62 mM)with 85% of the validation points falling within the A andB range of the Clarke error grid. Finally, to evaluate thereal-time response of the sensor, the 1/e time constantfor glucose partitioning and departitioning in the bovineplasma environment was calculated. The time constantis 28 s for partitioning and 25 s for departitioning,indicating the rapid interaction between the SAM andglucose that is essential for continuous sensing.