Portable microfluidic system for determination of urinary creatinine.
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).
Songjaroen
Temsiri
T
Graduate Program in Clinical Biochemistry and Molecular Medicine, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand.
Maturos
Thitima
T
Sappat
Aussawapong
A
Tuantranont
Adisorn
A
Laiwattanapaisal
Wanida
W
D003404:Creatinine / Q000652:urine*; D006863:Hydrogen-Ion Concentration; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods*; D010851:Picrates / Q000737:chemistry; D015203:Reproducibility of Results; D013696:Temperature; D013997:Time Factors
D010851:Picrates; C005858:picric acid; D003404:Creatinine