A centrifugally actuated point-of-care testing system for the surface acoustic wave immunosensing of cardiac troponin I

Analyst. 2013 May 7;138(9):2558-66. doi: 10.1039/c3an00182b.

Abstract

A fully automated point-of-care testing (POCT) system with a surface acoustic wave (SAW) immunosensor was developed for rapid and sensitive detection of cardiac troponin I (cTnI) in body fluid (plasma and whole blood). The assay, based on gold nanoparticle sandwich immunoassay and subsequent gold staining, was performed on the SAW immunosensor packaged inside a disposable microfluidic cartridge. The entire fluidic process, including plasma separation, reagent transport, metering, and mixing, was carried out by controlling the centrifugal force acting on the rotating cartridge and laser-irradiated ferrowax microvalves. On investigation of sensor response to various cTnI concentrations, the system exhibited a high performance with a detection limit of 6.7 pg mL(-1), and the coefficient of variation was less than 10% over the entire test range (10 pg mL(-1) to 25 ng mL(-1)). On comparing this POCT system with a clinically utilized system in a physical laboratory (Centaur® XP; Siemens), a correlation coefficient of 0.998 was found, validating the diagnostic capability of the SAW immunosensor.

Publication types

  • Validation Study

MeSH terms

  • Equipment Design
  • Gold / chemistry
  • Humans
  • Immunoassay / instrumentation*
  • Limit of Detection
  • Microfluidic Analytical Techniques / instrumentation*
  • Nanoparticles / chemistry
  • Point-of-Care Systems*
  • Sound
  • Troponin I / blood*

Substances

  • Troponin I
  • Gold