Development of rapid semi-quantitative point of care (POC) device for ammonia detection

全血中氨的检测在许多肝病的诊断和治疗中都有应用，包括肝硬变和罕见的尿素循环障碍。目前的氨测量技术存在量程有限、分辨率低、假阳性或大型复杂传感器设置等问题。目前的项目是开发一种方法和一次性使用的护理点设备，用于血液中氨的测试，包括所有化学试剂。其目的是开发一种利用廉价试剂和简单方法检测最小体积全血中氨的技术。由于我们的目标是从源头使用该试剂盒，最少的实验室程序和不需要样品处理步骤。因此，本研究旨在开发分离或保留血液样本中可能对氨的测量产生不利影响的红细胞或杂质的方法。该传感器将利用改进形式的吲酚反应，结合滤膜来抵抗血液中的破坏性干扰源。该产品将具有一种传感方案，对氨基酸等其他含有胺的分子具有选择性，保质期至少为50天。此外，改进后的系统将具有高灵敏度，可在25至500微米的最小范围内准确可靠地半定量测定全人类血液样本中的氨，这在临床上与罕见的高氨血症和肝病相关。

Ammonia detection in whole blood has applications in the diagnosis and management of many hepatic diseases, including cirrhosis and rare urea cycle disorders. Current techniques for ammonia measurement suffer from limited range, poor resolution, false positives or large, complex sensor set-ups. The current project is undertaken to develop a method and a disposable single-use point of care device for ammonia testing in blood including all chemical reagents. The aim is to develop a technique utilizing inexpensive reagents and simple methods for detecting ammonia in minimum volume of whole blood.Since, we aim this kit to be used at the source with minimum laboratory procedures and no sample processing steps. Hence, the present study will aim to develop methods to separate or withhold red blood cells or impurities in the blood sample that could adversely affect the measurement of ammonia. The sensor would exploit the modified form of the indophenol reaction, which resists sources of destructive interference in blood, in conjunction with a filter membrane.The product will have a sensing scheme that is selective against other amine containing molecules such as amino acids and has a shelf life of at least 50 days. Additionally, the resulting system will be modified to have high sensitivity and allows for the accurate reliable semi-quantification of ammonia in whole human blood samples at a minimum range of 25 to 500 µM, which is clinically relevant for rare hyperammonemic disorders and liver disease.