Institut für Biophysik, Goethe-Universität Frankfurt, Max von Laue-Strasse 1, 60438 Frankfurt am Main, Germany.
Anal Chem. 2013 Jan 15;85(2):1013-20. doi: 10.1021/ac302841f. Epub 2012 Dec 26.
The noninvasive determination of glucose in the interstitial layer of the human skin by mid-infrared spectroscopy is reported. The sensitivity for this measurement was obtained by combining the high pulse energy from an external cavity quantum cascade laser (EC-QCL) tunable in the infrared glucose fingerprint region (1000-1220 cm(-1)) focused on the skin, with a detection of the absorbance process by photoacoustic spectroscopy in the ultrasound region performed by a gas cell coupled to the skin. This combination facilitates a quantitative measurement for concentrations of skin glucose in the range from <50 mg/dL to >300 mg/dL, which is the relevant range for the glucose monitoring in diabetes patients. Since the interstitial fluid glucose level is representative of the blood glucose level and follows it without significant delay (<10 min), this method could be applied to establish a noninvasive, painless glucose measurement procedure that is urgently awaited by diabetes patients. We report here the design of the photoacoustic experiments, the spectroscopy of glucose in vivo, and the calibration method for the quantitative determination of glucose in skin. Finally, a preliminary test with healthy volunteers and volunteers suffering from diabetes mellitus demonstrates the viability of a noninvasive glucose monitoring for patients based on the combination of infrared QCL and photoacoustic detection.
本文报道了通过中红外光谱法无创测定人体皮肤间质层中的葡萄糖。通过将外部腔量子级联激光器（EC-QCL）的高脉冲能量与皮肤耦合的气体池的超声区域中的光声光谱检测相结合，获得了这种测量的灵敏度，该 EC-QCL 可调谐到红外葡萄糖指纹区域（1000-1220cm(-1))。这种组合便于对皮肤葡萄糖浓度进行定量测量，范围从<50mg/dL 到>300mg/dL，这是糖尿病患者血糖监测的相关范围。由于间质液葡萄糖水平代表血糖水平，并且没有明显延迟（<10 分钟），因此该方法可用于建立一种非侵入性、无痛的葡萄糖测量程序，这是糖尿病患者迫切需要的。我们在这里报告光声实验的设计、体内葡萄糖的光谱学以及皮肤中葡萄糖定量测定的校准方法。最后，对健康志愿者和糖尿病患者的初步测试证明了基于红外 QCL 和光声检测相结合的患者无创血糖监测的可行性。
