Electrochemical sandwich-type biosensors for α−1 antitrypsin with carbon nanotubes and alkaline phosphatase labeled antibody-silver nanoparticles

Gangbing Zhu, Hye Jin Lee

Research output: Contribution to journalArticlepeer-review

53 Scopus citations

Abstract

A novel sandwich-type biosensor was developed for the electrochemical detection of α−1 antitrypsin (AAT, a recognized biomarker for Alzheimer's disease). The biosensor was composed of 3, 4, 9, 10-perylene tetracarboxylic acid/carbon nanotubes (PTCA-CNTs) as a sensing platform and alkaline phosphatase-labeled AAT antibody functionalized silver nanoparticles (ALP-AAT Ab-Ag NPs) as a signal enhancer. CNTs offer high surface area and good electrical conductivity. Importantly, Ag NPs could increase the amount of ALP on the sensing surface and the ALP could dephosphorylate 4-amino phenyl phosphate (APP) enzymatically to produce electroactive species 4-aminophenol (AP). For detecting AAT based on the sandwich-type biosensor, the results show that the peak current value of AP using ALP-AAT Ab-Ag NPs as signal enhancer is much higher than that by using ALP-AAT Ab bioconjugate (without Ag NPs), the biosensor exhibited desirable performance for AAT determination with a wide linearity in the range from 0.05 to 20.0 pM and a low detection limit of 0.01 pM. Finally, the developed sensor was successfully applied to the analysis of AAT concentration in serum samples.

Original languageEnglish
Pages (from-to)959-963
Number of pages5
JournalBiosensors and Bioelectronics
Volume89
DOIs
StatePublished - 15 Mar 2017

Keywords

  • Alzheimer's disease
  • Antibody functionalized silver nanoparticles
  • Electrochemical biosensors
  • Sandwich assays
  • α−1 antitrypsin

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