Yun J H, Fu B, Meyerhoff M E, Yang V C
College of Pharmacy, University of Michigan, Ann Arbor 48109-1065, USA.
ASAIO J. 1994 Jul-Sep;40(3):M401-5. doi: 10.1097/00002480-199407000-00030.
The development of an ion-selective electrode heparin sensor consisting of a specially formulated polymer membrane doped with tridodecylmethylammonium chloride as the heparin complexing agent was recently reported. Because of the simple nature of the membrane technology used, the authors envisioned that the sensor could be configured as a disposable single-use device for rapid clinical or bedside measurement of heparin in a small, discrete sample. To explore this possibility, an inexpensive, disposable heparin sensor was created by dip-coating a copper wire with the specially formulated heparin-sensing polymeric membrane. Coated wire heparin sensors with a broad range of membrane thicknesses, prepared by repeatedly dipping the wire in the membrane solution for various times, were examined. Data show that increasing the membrane thickness of the sensor to a certain degree (more than 10 microns) enhanced the sensor's potentiometric response to heparin, although the time required to achieve 90% of the steady-state potential change was also prolonged. In addition, increasing membrane thickness also magnified the stirring effect on the sensor's response. In undiluted plasma samples, the coated-wire sensor with an optimized membrane thickness yielded a significant (5 to 30 mV) and reproducible response to heparin in a clinically relevant concentration range (0.5 to 12 units/ml, respectively). The clinical utility of the coated wire heparin sensor was shown using the sensor during protamine titration of heparinized plasma to assess the titration end-point. Preliminary results showed that the titration end-points determined by the heparin sensor strongly correlated with those determined by the activated partial thromboplastin time clotting assay. The overall time requirement to complete the titration process using a set of prefabricated coated wire heparin sensors, however, was less than 3 minutes. Further titration studies using undiluted clinical whole blood samples are in progress.
最近有报道称开发了一种离子选择性电极肝素传感器，该传感器由一种特殊配方的聚合物膜组成，膜中掺杂有氯化三癸基甲基铵作为肝素络合剂。由于所使用的膜技术性质简单，作者设想该传感器可以配置为一次性使用设备，用于在小的离散样本中快速进行临床或床边肝素测量。为了探索这种可能性，通过用特殊配方的肝素传感聚合物膜浸涂铜线，制造了一种廉价的一次性肝素传感器。对通过将导线在膜溶液中反复浸渍不同时间制备的具有广泛膜厚度范围的涂丝肝素传感器进行了研究。数据表明，将传感器的膜厚度增加到一定程度（超过10微米）可增强传感器对肝素的电位响应，尽管达到稳态电位变化的90%所需的时间也会延长。此外，增加膜厚度还会放大搅拌对传感器响应的影响。在未稀释的血浆样本中，具有优化膜厚度的涂丝传感器在临床相关浓度范围（分别为0.5至12单位/毫升）内对肝素产生了显著（5至30毫伏）且可重复的响应。在肝素化血浆的鱼精蛋白滴定过程中使用该传感器来评估滴定终点，展示了涂丝肝素传感器的临床实用性。初步结果表明，肝素传感器确定的滴定终点与活化部分凝血活酶时间凝血测定法确定的滴定终点密切相关。然而，使用一组预制的涂丝肝素传感器完成滴定过程的总体时间要求不到3分钟。使用未稀释的临床全血样本的进一步滴定研究正在进行中。
