Biosensors that continuously measure circulating biomolecules in real time could provide insights into the health status of patients and their response to therapeutics. But biosensors for the continuous real-time monitoring of analytes in vivo have only reached nanomolar sensitivity and can measure only a handful of molecules, such as glucose and blood oxygen. Here we show that multiple analytes can be continuously and simultaneously measured with picomolar sensitivity and sub-second resolution via the integration of aptamers and antibodies into a bead-based fluorescence sandwich immunoassay implemented in a custom microfluidic chip. After an incubation time of 30 s, bead fluorescence is measured using a high-speed camera under spatially multiplexed two-colour laser illumination. We used the assay for continuous quantification of glucose and insulin concentrations in the blood of live diabetic rats to resolve inter-animal differences in the pharmacokinetic response to insulin as well as discriminate pharmacokinetic profiles from different insulin formulations. The assay can be readily modified to continuously and simultaneously measure other blood analytes in vivo.

实时连续测量循环生物分子的生物传感器可以深入了解患者的健康状况及其对治疗的反应。但用于连续实时监测体内分析物的生物传感器仅达到纳摩尔级灵敏度，并且只能测量少数分子，例如葡萄糖和血氧。在这里，我们表明，通过将适体和抗体集成到定制微流控芯片中实施的基于珠子的荧光夹心免疫测定中，可以以皮摩尔灵敏度和亚秒分辨率连续、同时测量多种分析物。孵育 30 秒后，使用高速相机在空间复用双色激光照明下测量珠子荧光。我们使用该测定法对活体糖尿病大鼠血液中的葡萄糖和胰岛素浓度进行连续定量，以解决动物间对胰岛素药代动力学反应的差异，并区分不同胰岛素制剂的药代动力学特征。该测定可以很容易地进行修改，以连续、同时测量体内的其他血液分析物。