Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States.
Anal Chem. 2020 Mar 3;92(5):3860-3866. doi: 10.1021/acs.analchem.9b05313. Epub 2020 Feb 20.
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) and showed the fastest kinetics (2.1 × 10 M s) 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) 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.
这四种葡萄糖酯被合成并用于测定人滑膜（关节）液和尿液中的感染酶白细胞酯酶（LE）。酯类作为 LE 的底物，在样品中 LE 的活性呈直接比例释放葡萄糖。释放的葡萄糖随后通过偶联酶测定法在掺氮碳纳米管（N-CNT）电极或商业葡萄糖测试条上进行检测。在 N-CNT 电极上的测定法可以检测到低至 0.81 nM（25 μg L）的 LE，并且对其羰基周围空间最不拥挤的酯具有最快的动力学（2.1×10 M s）。当与葡萄糖测试条一起使用时，这些酯可以在微升大小的体液样本中分辨出高达至少 26 nM（800 μg L）的临床相关水平的 LE。使用电化学工作站（而非个人血糖仪（血糖计））读取葡萄糖测试条，将所需样本孵育时间从 3 小时缩短至 5 分钟。对孵育样本的信号进行校正，使其与原始样本的信号相匹配，消除了基质效应并解释了内源性葡萄糖的存在。这些新的酯类有可能将葡萄糖测试条（已经有数百万用于糖尿病监测）的用途扩展到对尿路感染和假体关节感染严重程度的定量检测。
