title: Strategy for increasing the electrode density of microelectrode arrays by utilizing bipolar behavior of a metallic film.
abstract: Recessed microelectrode arrays and plane-recessed microelectrode arrays (MEAs) with different center-to-center distances are designed and fabricated using lithographic technology. By comparing electrochemical behavior of plane-recessed MEAs with that of recessed MEAs, bipolar phenomenon of the metallic plane film is revealed. Redox cycling can occur when the top plane electrode was floating; that is, the bipolar behavior of the unbiased top plane electrode may perform locally as a collector and enlarge the concentration gradient of Ru(NH3)6Cl3 and thus promote an apparent generator/collector electrochemical response of the microdisk electrode in the MEAs configuration. By utilizing the bipolar behavior, the center-to-center distance of MEAs required for achieving steady-state current could decrease without favoring at the same time the overlapping of diffusion layers of microelectrodes, and thus, the electrode density of MEAs can be increased. Therefore, the bipolar behavior of the metallic film can increase both the current response of an individual microdisk and the electrode density of microdisks without losing the characteristics of a microelectrode. By just fabricating a thin layer of metallic film on the plane and leaving it floating without potential control, recessed MEAs used in this work can achieve the increase of detection sensitivity by more than 1 order of magnitude.
authors: State Key Laboratory for Physical Chemistry of Solid Surfaces, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen, Fujian 361005, People's Republic of China.
authors: Feng
authors: F
authors: Zhu
authors: Jiawei
authors: J
authors: Yan
authors: Shiwei
authors: S
authors: Pang
authors: Yongliang
authors: Y
authors: Zhou
authors: Bingwei
authors: B
authors: Mao
authors: Alexander
authors: A
authors: Oleinick
authors: Irina
authors: I
authors: Svir
authors: Christian
authors: C
authors: Amatore