A needle-type enzyme-based lactate sensor for in vivo monitoring

✍ Scribed by Yibai Hu; Yanan Zhang; George S. Wilson

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 754 KB
• Volume: 281
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(93)85008-8

✦ Synopsis

A miniature needle-type lactate sensor prepared by coupling the enzyme lactate oxidase (LCD) with an hydrogen peroxide probe has been developed which makes possible real-time in vivo lactate measurements. The sensor has a size of 0.35 mm o.d. with a cylindrical sensing cavity in which a multilayer detection element was placed. The linearity of sensor response was extended beyond the clinically relevant concentration range and the response time was about 30 seconds. Measurement of incubated plasma samples with lactate oxidase and catalase showed that the overall endogenous interferences caused a negligible error. In vitro characterization including effects of temperature, pH and PO2 and stability was carried out as well. In vivo tests in rat subcutaneous tissue showed that the sensors functioned reliably. Good correlation was observed between the sensor output and plasma lactate measured simultaneously in situ with a flow injection system. Potential oxygen effects were also measured in vivo and the results showed that the sensor can tolerate reasonably low tissue oxygen levels even for hypoxic conditions in which Paz was as low as 10 mmHg.