Determination Of Albumin Concentration Research Articles

Fast and simple detection of bovine serum albumin concentration by studying its interaction with gold nanorods

Nowadays, the detection of albumin and determination of its concentration for early diagnosis of kidney diseases has attracted considerable attention as a simple and rapid method. In this work, two methods for detection and determination of albumin concentration were investigated and compared by using gold nanorods (GNRs) and spectrophotometry of their interaction with bovine serum albumin (BSA).By the changes in the typical synthesis protocol, GNRs' samples were synthesized and characterized. Synthesized GNRs were mixed with different concentrations of BSA. Ultraviolet–Visible (UV–Vis) spectroscopy and X-ray Fluorescence (FL) spectroscopy were applied to examine the mixed samples. The change of absorption spectrum in the UV region showed the detection limit of BSA concentration of 0.2 mg/mL. The detection limit of BSA concentration of 0.05 mg/mL was obtained from the investigation of absorption spectrum in visible-infrared (Vis-IR) regions. However, the study of the FL spectra proved the detection limit is as low as 0.0013 mg/mL. Therefore, it was found out that very low concentrations of albumin could be very accurately detected by FL spectroscopy. Also, comparing of the spectra obtained from the samples at various time intervals indicated that the measurement of concentration is possible after 1–20 min of mixing GNRs and BSA.

Determination of albumin concentration by MIP-QCM sensor

An MIP-QCM sensor able to detect micro-determine albumin concentrations was prepared by imprinting albumin with 3-dimethylaminopropyl methacrylamide-acrylate. The albumin MIP was coated on a QCM Au electrode. The adsorption characteristics of different electrodes, such as Au–OH, Au–COOH, Au–NH 2 and Au electrodes, with albumin or mixture was examined. In the tetraethyleneglycol dimethacrylate crosslinking agent system, the adsorption capacity of different Au electrodes is in the order Au–OH > Au–COOH > Au–NH 2 > Au. Additionally, the time taken to receive a steady-state frequency is in the order Au–NH 2 < Au–OH < Au–COOH < Au. However, in the trimethylolpropane trimethacrylate crosslinking agent system, the adsorption capacity is in the order Au > Au–NH 2 > Au–OH > Au–COOH electrode. Hence, the crosslinking agent had a significant effect on the MIP-QCM. On the adsorption selectivity, the albumin MIP-QCM exhibited higher response to albumin, the adsorption mass ratio of cytochrome c:lysozyme:albumin:myoglobin was 160:1:1942:30. On the other hand, in the non-MIP-QCM, the adsorption mass ratio of cytochrome c:lysozyme:albumin:myoglobin was 13:1:249:86. Additionally, a linear fitting was established and a clinical real sample was tested. This novel potential application of molecular imprinting to the recognition element of an MIP-QCM sensor appears to be promising.

Albumin excretion rate, albumin concentration, and albumin/creatinine ratio compared for screening diabetics for slight albuminuria.

Slight albuminuria, an overnight albumin excretion rate (AER) greater than 30 micrograms/min in an "Albustix"-negative sample, predicts development of diabetic nephropathy. This study compares the AERs for 261 timed overnight urine collections with the albumin concentrations and albumin/creatinine ratios for the same specimens (equivalent to first morning specimens). Thirty-one specimens (11.9%) had AERs greater than 30 micrograms/min. Use of an albumin/creatinine ratio greater than 3.0 mg/mmol to predict an AER greater than 30 micrograms/min gave a sensitivity of 96.8%, a specificity of 93.9%, and a predictive value of 68.2%, with a correlation coefficient of 0.921. Use of an albumin concentration greater than 17 mg/L gave a sensitivity of 96.8%, a specificity of 90.9%, a predictive value of 58.8%, and a slightly poorer correlation (r = 0.904). Evidently either method is acceptable as an initial screening procedure, but determination of albumin concentration alone would be preferable because of lesser cost.