Portable microfluidic system for determination of urinary creatinine

Anal Chim Acta. 2009 Aug 4;647(1):78-83. doi: 10.1016/j.aca.2009.05.014. Epub 2009 May 20.

Abstract

A simple, low cost and portable microfluidic system based on a two-point alkaline picrate kinetic reaction has been developed for the determination of urinary creatinine. The creatinine reacts with picric acid under alkaline conditions, forming an orange-red colour, which is monitored on PDMS microchip using a portable miniature fibre optic spectrometer at 510 nm. A linear range was displayed from 0 to 40 mg L(-1) creatinine (r2 = 0.997) with a detection limit of 3.3 mg L(-1) (S/N = 3). On-chip absorbance signals are reproducible, with relative standard deviations (RSDs) of 7.1%, when evaluated with 20 mg L(-1) creatinine (n = 10). The standard curves in which the intra-run CVs (4.7-6.8%) and inter-run CVs (7.9%) obtained were performed on three different days and exhibited good reproducibility. The method was highly correlated with the conventional spectrophotometric method when real urine samples were evaluated (r2 = 0.948; n = 15).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Creatinine / urine*
  • Hydrogen-Ion Concentration
  • Microfluidics / instrumentation*
  • Microfluidics / methods*
  • Picrates / chemistry
  • Reproducibility of Results
  • Temperature
  • Time Factors

Substances

  • Picrates
  • picric acid
  • Creatinine