A microfluidic platform or “microfluidic batch adsorption device” is presented, which performs two sets of 9 parallel protein incubations with/without adsorbent particles to achieve an adsorption isotherm of a protein in a single experiment. The stepwise concentration gradient of a target protein was created by the integration of microvalves into the device. The nanoliter-scale reactor (41 nl) allows about 5000 times reduction of sample consumption and fast analysis compared with a conventional 96 well plate. The integration of two sets of parallel reactors as reference reactors and adsorption reactors, respectively, in a single microfluidic format has many advantages, such as the exclusion of the influence of undesired experimental fluctuations, and the possibility of real-time tracing of adsorption processes. We performed batch adsorption of albumin–fluorescein isothiocyanate conjugate (FITC-BSA) on polymeric particles (Source 15Q) to obtain an adsorption isotherm. The obtained on-chip parameters maximum adsorption amount (Q_max) and adsorption constant (K_eq) were 0.33 ± 0.03 ng per particle and 0.97 ± 0.22 L g⁻¹, respectively, which are in good agreement with off-chip values (Q_max = 0.34 ± 0.01 ng per particle and K_eq = 0.81 ± 0.10 L g⁻¹). On-chip adsorption isotherms of FITC-BSA at various concentrations of sodium chloride (NaCl) were measured to evaluate the effect of this salt on the adsorption capability of Source 15Q. The microfluidic device serves as a new analytical tool, useful in biotechnological and industrial applications, where the adsorption behavior of (bio)molecules on commercial adsorbent particles plays critical roles, such as protein separation and purification, detection of analytes and biomarkers, and solid-phase immunoassays.

中文翻译：

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用于将蛋白质分批吸附在吸附剂颗粒上的微流控设备

提出了一种微流控平台或“微流批吸附装置”，该平台在有/无吸附剂颗粒的情况下执行两组9个平行蛋白质温育，以在单个实验中实现蛋白质的吸附等温线。通过将微阀集成到设备中来创建目标蛋白质的逐步浓度梯度。与传统的96孔板相比，纳升级反应器（41 nl）可使样品消耗减少约5000倍，并且分析速度更快。将两组平行反应器分别作为参考反应器和吸附反应器以单个微流体形式进行集成具有许多优点，例如排除了不希望的实验波动的影响以及实时追踪吸附过程的可能性。我们在聚合物颗粒（来源15Q）上进行了白蛋白-荧光素异硫氰酸荧光素共轭物（FITC-BSA）的分批吸附，以获得吸附等温线。获得的片上参数最大吸附量（Q _max）和吸附常数（K _eq）分别为0.33±0.03 ng /颗粒和0.97±0.22 L g ^-1，与片外值（Q _max = 0.34±0.01 ng /颗粒和K _eq = 0.81±0.10升g ^-1）。测量了FITC-BSA在各种浓度的氯化钠（NaCl）上的片上吸附等温线，以评估该盐对Source 15Q吸附能力的影响。微流体装置可作为一种新的分析工具，可用于生物技术和工业应用，其中（生物）分子在商业吸附剂颗粒上的吸附行为起着至关重要的作用，例如蛋白质分离和纯化，分析物和生物标志物的检测以及固体-阶段免疫测定。