Surface-based biosensing devices benefit from a dedicated design of the probe layer present at the transducing interface. The layer architecture, its physicochemical properties, and the embedding of the receptor sites affect the probability of binding the analyte. Here, the enhancement of the probe density at the sensing interface by tuning the exponential growth regime of polyelectrolyte multilayers (PEMs) is presented. PEMs were made of poly-l-lysine (PLL), with appended clickable dibenzocyclooctyne (DBCO) groups and oligo(ethylene glycol) chains, and poly(styrene sulfonate) (PSS). The DNA probe loading and target hybridization efficiencies of the PEMs were evaluated as a function of the PLL layer number and the growth regime by a quartz crystal microbalance (QCM). An amplification factor of 25 in the target DNA detection was found for a 33-layer exponentially grown PEM compared to a monolayer. A Voigt-based model showed that DNA probe binding to the DBCO groups is more efficient in the open, exponentially grown films, while the hybridization efficiencies appeared to be high for all layer architectures. These results show the potential of such engineered gel-like structures to increase the detection of bio-relevant analytes in biosensing systems.
展开▼
机译：基于表面的生物传感设备受益于转导界面处探针层的专用设计。层结构、物理化学性质和受体位点的包埋会影响结合分析物的可能性。本文介绍了通过调节聚电解质多层膜（PEMs）的指数生长机制来增强传感界面的探针密度。PEMs由聚-l-赖氨酸（PLL）和聚苯乙烯磺酸酯（PSS）组成，并附加了可点击的二苯并环辛炔（DBCO）基团和低聚乙二醇链。通过石英晶体微天平 （QCM） 评估 PEM 的 DNA 探针负载和靶标杂交效率作为 PLL 层数和生长状态的函数。与单层PEM相比，33层指数增长的PEM在靶DNA检测中发现扩增因子为25。基于Voigt的模型表明，在开放的指数生长薄膜中，DNA探针与DBCO基团的结合效率更高，而所有层结构的杂交效率似乎都很高。这些结果表明，这种工程凝胶状结构在增加生物传感系统中生物相关分析物检测的潜力。
展开▼
