Characterizing functionalized electrode surfaces with unique spectroelectrochemical methods for biosensor development

电化学过程构成了许多新技术的基础(例如。电池、燃料电池、太阳能电池)以及生物分析传感方法。这些传感器的便携性和占地面积小&它们集成到智能手机中将有助于进行护理点分析确定，为此需要开发灵敏、特定和强大的传感器。实现这一目标将需要表征和控制这些表面的功能化，这是本研究计划的核心。我们开发了新的方法来研究电化学过程中这些复杂的界面(原位)。 基于电化学的生物传感器依赖于用生物活性物质(如脂类、核酸或酶)修饰电极表面，这些生物活性物质可以与样品中感兴趣的化合物特异地相互作用，然后将这种相互作用转化为可以准确测量的信号。这需要对传感器表面的准备进行高水平的控制。生物传感器必须在表面上有足够数量的探针，这些探针可以被溶液中的目标接触到，这样当特定地相互作用时，将在测量信号中产生变化。通过控制表面结构来控制探头密度、探头分布、减少非特异性相互作用(噪声)，将有助于功能化表面的改进，并延伸到新的生物传感器转导基元的开发。 多年来，电化学界面的表征一直是我们研究的重点。我们开发了一种独特的原位荧光显微镜方法，用于在控制电化学电位的同时分析这些界面。这是通过使用标记为吸附的荧光团来实现的。测量的荧光依赖于荧光团从电极表面的分离，当接近5 nm时荧光被猝灭。我们的方法使我们能够详细了解这些修饰表面的结构，从大尺度(亚毫米)到分子尺寸范围(10s纳米)，以及这如何依赖于表面晶体结构和功能化方法(多步吸附、共吸附、电位控制吸附、官能化表面的化学修饰)。我们继续改进我们的原位表征方法，将共聚焦显微镜与荧光寿命成像结合起来。这些新的分析方法将用于创建复杂的表面；从多组分的表面到量子点装饰的表面。我们的长期目标是设计出在使用先进的原位表征技术的指导下，创建具有最佳功能的生物传感器表面的方法。这是我们将用来影响定义良好的生物传感器以及更广泛地说所有类型的功能化表面的创建的基本原则。

Electrochemical processes form the basis of many new technologies (eg. batteries, fuel cells, solar cells) as well as approaches to bioanalytical sensing. The portability and small footprint of these sensors & their integration into smart phones will facilitate point of care analytical determinations, for which sensitive, specific and robust sensor development is required. Achieving this goal will require characterizing and controlling the functionalization of these surfaces which is at the core of this research program. We develop new methods to investigate these complex interfaces during electrochemical processes (in-situ). Electrochemical based biosensors rely on the modification of the electrode surface with biologically active species (eg lipids, nucleic acids or enzymes) that can specifically interact with compounds of interest in the sample, and then transduce this interaction into a signal that can be measured accurately. This requires a high level of control over the preparation of the sensor surface. A biosensor must have a sufficient number of probes on the surface which are accessible by the targets in solution so that when specifically interacting, will create a change in the measured signal. Controlling the probe density, probe distribution, reducing the non-specific interactions (noise) by controlling the surface structures will enable improvement of the functionalized surfaces with extension to development of new biosensor transduction motifs. Characterizing the electrochemical interface has been the focus of our research efforts for many years. We have developed a unique in-situ fluorescence microscopic method for analyzing these interfaces while controlling the electrochemical potential. This is accomplished by using a fluorophore labelled adsorbate. The fluorescence measured depends on the separation of the fluorophore from the electrode surface with fluorescence quenched when closer than 5nm. Our method enables a detailed understanding of the structure of these modified surfaces, from large scales (sub mm) to molecular sized regimes (10s of nm) and how this depends on the surface crystallography and the functionalization method (multiple step adsorption, co-adsorption, potential-controlled adsorption, chemical modification of the functionalized surface). We continue to advance our in-situ characterization method to include confocal microscopy with fluorescence lifetime imaging. These new analysis methods will be used in creating complex surfaces; from multi-component surfaces, to quantum dot decorated surfaces. Our long term goal is to devise methods for creating biosensor surfaces which are optimally functional guided by the use of advanced in-situ characterization techniques. This is the foundational principle which we will use to influence the creation of well defined biosensors and, more broadly all types of functionalized surfaces.