Alkaline Phosphatase-Catalyzed Silver Deposition for Electrochemical Detection

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• 作者：Pablo Fanjul-Bolado ; David Herná ; ndez-Santos ; Mar&iacute ; a Begoñ ; a Gonzá ; lez-Garc&iacute ; a ; Agust&iacute ; n Costa-Garc&iacute ; a
• 刊名：Analytical Chemistry
• 出版年：2007
• 出版时间：July 15, 2007
• 年：2007
• 卷：79
• 期：14
• 页码：5272 - 5277
• 全文大小：194K
• 年卷期：v.79,no.14(July 15, 2007)
• ISSN：1520-6882

文摘

Alkaline phosphatase (AP) is one of the most usedenzymatic labels for the development of ELISAs, immunosensors, DNA hybridization assays, etc. This enzymecatalyzes the dephosphorylation of a substrate into adetectable product usually quantified by optical or electrochemical measurements. This work is based on asubstrate (3-indoxyl phosphate) that produces a compound able to reduce silver ions in solution into a metallicdeposit, which is localized where the enzymatic label APis attached. The deposited silver is electrochemicallystripped into solution and measured by anodic strippingvoltammetry. Its application to an enzymatic genosensoron streptavidin-modified screen-printed carbon electrodesfor the detection of virulence nucleic acid determinantsof autolysin gene, exclusively present on the genome ofthe human pathogen Streptococcus pneumoniae, isdescribed. Compared with the direct voltammetric detection of indigo carmine, the anodic stripping voltammetryof silver ions is 14-fold more sensitive.