基于微流控和酶比色的微创血糖连续检测仪

连续血糖检测对糖尿病的诊断与治疗具有十分重要的意义。本文设计了一种集成化、自动化的微创血糖连续检测仪器,该仪器通过微流控芯片透皮抽取组织液,利用单片机精确测量透皮抽取组织液的体积,并采用酶比色法检测组织液的葡萄糖浓度,利用组织液与血液的葡萄糖浓度相关性实现连续血糖检测。由于透皮抽取的组织液体积很小且分散在皮肤表面,为了便于收集,利用生理盐水对抽取出的组织液进行稀释,稀释后的组织液中葡萄糖浓度在3～50mg/dL。为了测量低浓度葡萄糖,实验选取了1～50mg/dL中的10个浓度的葡萄糖溶液进行吸光度测量,根据光谱数据与葡萄糖浓度建立吸光度模型,结果表明该酶比色检测方法在1～50mg/dL葡萄糖浓度内具有良好的线性度,测量相对标准偏差小于0.65%。该仪器能够实现自动化控制,为糖尿病的诊断提供依据,在微创血糖连续检测领域具有良好的应用前景。

Minimally invasive continuous blood glucose monitor based on microfluidic and enzyme colorimetric technologies

Continuous blood glucose detection is of great significance in the diagnosis and treatment of diabetes. In this study, an integrated, automated minimally invasive blood glucose continuous detection instrument was designed. Interstitial fluid (ISF) was transdermally extracted by a microfluidic chip, and the volume of the ISF was accurately measured by the single-chip computer. The glucose contained in the fluid was detected by enzyme colorimetry. Then, continuous blood glucose detection was achieved using the correlation of glucose concentration between the interstitial fluid and blood. The glucose concentration in the ISF was obtained by controlling the sample injection, reagent quantification, and absorbance detection in the enzyme colorimetric optical detection module. Owing to the small volume of the ISF extracted through the skin and dispersed on the surface of the skin, in order to facilitate collection, the extracted ISF was diluted with normal saline. To measure the low concentration of the diluted ISF, 10 concentrations in the range of 1-50 mg/dL were selected for absorbance measurement. The absorbance model was established based on the spectral data and glucose concentration. The results show that the glucose detection method has good linearity in the range of 1-50 mg/dL, and the relative standard deviation is less than 0.65%. The instrument is an automation control system and can provide basis for the diagnosis of diabetes. The feasibility of the instrument is verified by test experiments. The instrument has good application prospects for continuous blood glucose monitoring.