Portable microfluidic system for determination of urinary creatinine

An integrated microfluidic system for the determination of microalbuminuria by measuring the albumin-to-creatinine ratio

“…It is noted that many compounds normally existing in urine samples can interfere the creatinine measurements (Weber and van Zanten 1991). However, the interferences from urine samples for creatinine measurements have been found to be rarely observed since dilution factors as high as 50-100 (e.g., a 50-fold dilution in our case) are required prior to measurements, leading to a diminishing effect on interferences (Sakai et al 1995;Songjaroen et al 2009). For determining creatinine concentrations based on light absorbance measurements in our system, each of the 40 centrifuged urine samples is diluted 50-fold in 0.1 N HCl followed by measuring the concentration 20 times and averaging the results.…”

“…As shown in Fig. 7a, the reaction mitigates with the reaction time due to the inherent characteristic of the Jaffé reaction (Husdan and Rapoport 1968;Narayanan and Appleton 1980;Songjaroen et al 2009). Moreover, for a low concentration such as 1 mg/l, the reaction is completed within 1 min.…”

“…This assay provides a simple, rapid, and convenient tool for the determination of creatinine in both urine and serums. A microfluidic system connected with a syringe pump for delivering samples/ reagents and a portable fiber optic spectrometer for detecting the light absorption by the Jaffé reaction was reported recently (Songjaroen et al 2009). Using this system, an assay range of 0-40 mg/l with a detection limit of 3.3 mg/l was obtained and the creatinine concentrations from 15 urine samples were determined to have a strong correlation with those measured by the conventional spectrophotometric method.…”

Two low-cost digital camera-based platforms for quantitative creatinine analysis in urine

“…However, the presence of non-creatinine chromogens in the sample, which also react with alkaline picrate, can significantly blur the color development. To reduce color misinterpretation it should be considered that interferents are more likely to react late in the reaction [34]. This situation can be spotted by the formation of a plateau in absorbance values measured after several minutes.…”

An Integrated UV-Vis Microfluidic Device for the Study of Concentrated Solvent Extraction Reactions

“…Generally, the integration of UV-Vis spectroscopy onto microfluidic platforms is difficult since the typical path length is in the order of 10 -4 cm and the intensity of the signal at the detector is weak [23,24]. Thus, methods that differ from traditional UV-Vis spectroscopy and/or strategies to increase the optical path length are often sought [22,[26][27][28][29][30].…”