Point-of-Care Assay Platform for Quantifying Active Enzymes to Femtomolar Levels Using Measurements of Time as the Readout

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• 作者：Gregory G. Lewis ; Jessica S. Robbins ; Scott T. Phillips
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：November 5, 2013
• 年：2013
• 卷：85
• 期：21
• 页码：10432-10439
• 全文大小：422K
• 年卷期：v.85,no.21(November 5, 2013)
• ISSN：1520-6882

文摘

This Article describes a strategy for quantifying active enzyme analytes in a paper-based device by measuring the time for a reference region in the paper to turn green relative to an assay region. The assay requires a single step by the user, yet accounts for variations in sample volume, assay temperature, humidity, and contaminants in a sample that would otherwise prevent a quantitative measurement. The assay is capable of measuring enzymes in the low to mid femtomolar range with measurement times that range from 30 s to 15 min (lower measurement times correspond to lower quantities of the analyte). Different targets can be selected in the assay by changing a small molecule reagent within the paper-based device, and the sensitivity and dynamic range of the assays can be tuned easily by changing the composition and quantity of a signal amplification reagent or by modifying the configuration of the paper-based microfluidic device. By tuning these parameters, limits-of-detection for assays can be adjusted over an analyte concentration range of low femtomolar to low nanomolar, with dynamic ranges for the assays of at least 1 order of magnitude. Furthermore, the assay strategy is compatible with complex fluids such as serum.