Polyethylenimine Redox Polymers for Bioelectrocatalysis

燃料电池通过阳极的氧化反应和阴极的还原反应将化学能直接转化为电能。在酶生物燃料电池中，传统的燃料电池催化剂（如Pt、Pd、Ru）被阳极的燃料氧化酶（如葡萄糖氧化酶、酒精脱氢酶、果糖脱氢酶）和阴极的氧还原酶（如漆酶、胆红素氧化酶）所取代。目前，酶生物燃料电池的主要限制是低功率输出和有限的寿命。俄克拉荷马大学诺曼校区的首席研究员David Schmidtke和Daniel Glatzhofer对这些限制因素进行了假设。在酶生物燃料电池中，大多数酶的氧化还原中心都隐藏在蛋白质外壳中，电上无法接近。因此，大多数氧化还原酶通常不与电极交换电子。他们提议通过合成氧化还原聚合物来增加酶生物燃料电池的功率输出，这种聚合物可以增加氧化还原酶和电极之间的电子转移速率（即电流流动）。这些新型的基于pei的氧化还原聚合物通过在酶的氧化还原中心和电极表面之间有效地收集和穿梭电子来产生高电流。这些聚合物含有金属种，二茂铁化合物，与聚合物相连。调整系统需要合成具有不同间隔臂长度的聚合物。pi的目标是将功率输出提高20-200倍。酶生物燃料电池不能解决国家的能源需求。然而，随着对便携式能源需求的增加，也产生了对可替代可再生能源的需求。酶生物燃料电池是一种有吸引力的能量转换技术，因为它们在20-40℃的温和温度下工作。并消耗生物系统中容易获得的糖等底物。由于其固有的选择性，酶基阳极和阴极可以在相同的隔室中工作，而不需要分离膜，从而减小了尺寸和重量。它们在体内（例如起搏器、植入式传感器）和离体（例如远程站点传感、移动电子）系统中都有潜在的应用。研究人员打算用他们的研究作为一种工具，以增加该领域对潜在学生的吸引力。他们基于研究的信念是，学生对科学的态度和他在科学上的成就随着实践经验的提高而提高。为了帮助增加学生继续学习科学和工程的可能性，建议的教育活动包括本科生研究机会和弱势群体暑期研究实习机会，并与中学教师研究机会相匹配。

0967988SchmidtkeFuel cells convert chemical energy directly into electricity through an oxidation reaction at the anode and a reduction reaction at the cathode. In enzymatic biofuel cells, traditional fuel cell catalysts (e.g. Pt, Pd, Ru) are replaced by fuel oxidizing enzymes (e.g. Glucose Oxidase,Alcohol Dehydrogenase, Fructose Dehydrogenase) at the anode and oxygen reducing enzymes (e.g. Laccase, Bilirubin Oxidase) at the cathode. Currently the main limitations of enzymatic biofuel cells are low power output and limited lifetimes. Principal Investigators David Schmidtke and Daniel Glatzhofer at the University of Oklahoma, Norman Campus have hypothesized on the limiting factors. In enzymatic biofuel cells, the redox center of most enzymes is buried in the protein shell and electrically inaccessible. Thus most redox enzymes do not normally exchange electrons with an electrode. They propose to increase the power output of enzymatic biofuel cells by synthesizing redox polymers that increase the rate of electron transfer (i.e. current flow)between the redox enzymes and electrodes. These novel PEI-based redox polymers produce high currents by efficiently collecting and shuttling electrons between the enzyme¡¦s redox center and the electrode surface. These polymers contain metal species, ferrocene compounds, linked to the polymer. Tuning the system will require synthesis of polymers with different lengths of spacer arms. The PIs are targeting a 20-200 fold improvement in power output. Enzymatic biofuel cells will not solve the nation¡¦s energy needs. However, as the demand for portable energy increases, there develops a need for alternative renewable energy sources. Enzymatic biofuel cells are an attractive energy conversion technology because they operate at mild temperatures of20-40?aC and under neutral pH and consume substrates such as sugars that are readily available in biological systems. Because of their inherent selectivities, enzyme based anodes and cathodes can operate in the same compartment without separating membranes thereby reducing size and weight. They have potential applications for both in vivo (e.g. pacemakers, implantable sensors) and ex vivo (e.g. remote site sensing, mobile electronics) systems. The investigators intend to use their research as a vehicle to increase the attractiveness of the field to potential students. Their belief, based on studies, is that a student¡¦s attitude toward science and his achievement in science improves with hands-on experiences. To help increase the likelihood that students will continue their studies in science and engineering, proposed educational activities with research opportunities include Research Opportunities for Undergraduate students and Summer Research Internships for Underrepresented Groups, matched with Research Opportunities for Middle School Teachers.