National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Pathumthani 12120, Thailand.
Postharvest and Processing Research and Development Division, Department of Agriculture, Bangkok 10900, Thailand.
Biosensors (Basel). 2022 Oct 24;12(11):915. doi: 10.3390/bios12110915.
The instability of human serum albumin (HSA) in urine samples makes fresh urine a requirement for microalbumin analyses using immunoturbidimetry. Here, we determined the ability of an aptasensor-based fluorescent platform to detect microalbumin in old, boric acid-preserved urine samples. Our results show that the cleavage site of protease enzymes on urine albumin protein differed from the binding position of the aptamer on HSA protein, suggesting the aptasensor may be effective for albumin detection in non-fresh urine. Furthermore, the addition of boric acid in urine samples over a short term (at ambient temperature (T) and 4 °C), long term (-20 and -80 °C), and following freeze-thawing (1-3 cycles) did not significantly affect albumin stability, as analyzed using the aptasensor. Therefore, boric acid stabilized has in urine stored over a short- and long-term. Thus, the aptasensor developed by us is applicable for HSA detection in boric acid-preserved urine that has been stored for 7-d at T and 4 °C, and in the long-term at -80 °C.
人血清白蛋白（HSA）在尿液样本中的不稳定性使得使用免疫比浊法进行微量白蛋白分析需要使用新鲜尿液。在这里，我们确定了基于适体的荧光平台检测硼酸保存的陈旧尿液样本中微量白蛋白的能力。我们的结果表明，蛋白酶酶在尿液白蛋白蛋白上的裂解位点与 HSA 蛋白上适体的结合位置不同，这表明适体传感器可能可用于非新鲜尿液中的白蛋白检测。此外，硼酸在尿液样本中的短期（在环境温度（T）和 4°C）、长期（-20 和-80°C）以及反复冻融（1-3 次）添加均不会显著影响白蛋白稳定性，如使用适体传感器分析的那样。因此，硼酸在短时间和长时间内稳定了尿液中的白蛋白。因此，我们开发的适体传感器可适用于硼酸保存的尿液中 HSA 的检测，这些尿液在 T 和 4°C 下可保存 7 天，在-80°C 下可长期保存。
