作者:Michael Bekhit、Hua-Yu Wang、Stanton McHardy、Waldemar Gorski
DOI:10.1021/acs.analchem.9b05313
日期:2020.3.3
The four glucosyl esters were synthesized and tested for the determination of infection enzyme leukocyte esterase (LE) in human synovial (joint) fluid and urine. The esters acted as LE substrates releasing glucose in a direct proportion to the activity of LE in a sample. The freed glucose was then detected by a coupled-enzyme assay at either a nitrogen-doped carbon nanotube (N-CNT) electrode or a commercial glucose test strip. The assays at the N-CNT electrode detected LE down to 0.81 nM (25 μg L–1) and showed the fastest kinetics (2.1 × 105 M–1 s–1) for esters with the least crowded space around their carbonyl group. When used with glucose strips, the esters discerned clinically relevant levels of LE up to at least 26 nM (800 μg L–1) in the microliter-sized samples of bodily fluids. The reading of glucose strips with a potentiostat, instead of a personal glucose meter (blood glucometer), shortened the time of required sample incubation from 3 h to 5 min. Correcting the signal of incubated sample for that of original sample eliminated matrix effects and accounted for the presence of native glucose. The new esters have a potential to extend the use of glucose strips (already used by millions for diabetes monitoring) to the quantification of the severity of urinary tract and periprosthetic joint infections.
这四种葡萄糖苷酯被合成并用于检测人类滑膜(关节)液和尿液中感染酶白细胞酯酶(LE)。这些酯作为LE的底物,释放的葡萄糖与样本中LE的活性成正比。然后,通过在氮掺杂碳纳米管(N-CNT)电极或商业葡萄糖测试条上的耦合酶测定法检测释放的葡萄糖。在N-CNT电极上的测定可以检测到0.81 nM(25 μg L–1)的LE,并且对于碳酰基周围空间最少的酯,显示了最快的动力学(2.1 × 10^5 M–1 s–1)。当与葡萄糖测试条一起使用时,这些酯可以在微升体液样本中识别出至少达到临床相关水平的LE,值高达26 nM(800 μg L–1)。使用电位计读取葡萄糖测试条,而不是个人葡萄糖仪(血糖仪),将所需的样本培养时间从3小时缩短到5分钟。对培养样本的信号进行纠正以反映原始样本的信号,消除了基质效应,并考虑了内源性葡萄糖的存在。这些新的酯有潜力将葡萄糖测试条(已为数百万糖尿病监测者使用)扩展到尿路和关节假体周围感染严重程度的量化。