Optimization of gold nanoparticle-based real-time colorimetric assay of dipeptidyl peptidase IV activity

ALDEWACHI, Hasan, WOODROOFE, Nicola, TUREGA, Simon and GARDINER, Philip (2017). Optimization of gold nanoparticle-based real-time colorimetric assay of dipeptidyl peptidase IV activity. Talanta, 169, 13-19.

[img] PDF
Optimization of gold nanoparticle-based real-time colorimetric assay of dipeptidyl peptidase IV activity.pdf - Accepted Version
Restricted to Repository staff only until 18 March 2018.
Available under License All rights reserved.

Download (1MB) | Contact the author
[img] PDF (Supporting information)
Aldewachi Optimization of gold nanoparticle - Supporting material.pdf - Supplemental Material
Restricted to Repository staff only until 18 March 2018.
Available under License All rights reserved.

Download (355kB) | Contact the author
Official URL: http://www.sciencedirect.com/science/article/pii/S...
Link to published version:: /10.1016/j.talanta.2017.03.039

Abstract

Dipeptidyl peptidase IV (DPP-IV also referred to as CD-26) is a serine protease enzyme with remarkable diagnostic and prognostic value in a variety of health and disease conditions. Herein, we describe a simple and real-time colorimetric assay for DPP-IV/CD-26 activity based on the aggregation of gold nanoparticles (AuNPs) functionalized with the peptide substrates: Gly-Pro-Asp-Cys (GPDC) or Val-Pro-ethylene diamine-Asp-Cys (VP-ED-DC). Cleavage of the substrates by DPP-IV resulted in aggregation of the AuNPs with accompanying color change in the solution from red to blue that was monitored using either a UV–visible spectrophotometer or by the naked eye. Factors, such as time course of the reaction, stability of the functionalized AuNPs and the structure of the substrate that influence the cleavage reaction in solution were investigated. The effects of potential interference from serum proteins (lysozyme, thrombin and trypsin) on the analytical response were negligible. The detection limits when GPDC or VP-EN-DC functionalized AuNPs were used for DPP-IV assay were 1.2 U/L and 1.5 U/L, respectively. The VP-EN-DC method was preferred for the quantitative determination of DPP-IV activity in serum because of its wide linear range 0–30 U/L compared to 0–12 U/L for the GPDC assay. Recoveries from serum samples spiked with DPP-IV activity, between 5 and 25 U/L, and using the VP-EN-DC modified AuNPs method ranged between 83.6% and 114.9%. The two colorimetric biosensors described here are superior to other conventional methods because of their simplicity, stability, selectivity and reliability.

Item Type: Article
Uncontrolled Keywords: Gold nanoparticles Colorimetric assay Peptide substrates and DPP-IV enzyme activity
Research Institute, Centre or Group: Biomolecular Sciences Research Centre
Identification Number: /10.1016/j.talanta.2017.03.039
Depositing User: Hasan Aldewachi
Date Deposited: 24 Mar 2017 09:44
Last Modified: 20 Sep 2017 19:09
URI: http://shura.shu.ac.uk/id/eprint/15430

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics