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。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***电化学生物传感器依赖于电极表面的生物活性物质（如脂质，核酸或酶）的修饰，这些物质可以特异性地与样品中感兴趣的化合物相互作用，然后将这种相互作用转化为可以精确测量的信号。这需要对传感器表面的制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，这样当特定的相互作用时，就会在被测量的信号中产生变化。通过控制表面结构来控制探针密度、探针分布、减少非特异性相互作用（噪声）将使功能化表面得到改善，并扩展到新的生物传感器转导基序的开发。电化学界面的表征是我们多年来研究的重点。我们开发了一种独特的原位荧光显微方法来分析这些界面，同时控制电化学电位。这是通过使用荧光团标记的吸附物来完成的。测量的荧光取决于荧光团与电极表面的分离，当距离小于5nm时荧光猝灭。我们的方法能够详细了解这些修饰表面的结构，从大尺度（亚毫米）到分子尺度（10s nm），以及这如何取决于表面晶体学和功能化方法（多步吸附、共吸附、电位控制吸附、功能化表面的化学改性）。我们继续推进我们的原位表征方法，包括共聚焦显微镜与荧光寿命成像。这些新的分析方法将用于创建复杂的表面；从多组分表面，到量子点装饰表面。我们的长期目标是通过使用先进的原位表征技术，设计出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创建定义良好的生物传感器的基本原则，更广泛地说，所有类型的功能化表面。**

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 ***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. **