We are interested in all things electrochemical. In particular, as the size of the electrodes move into the nanometer regime, a number of interesting phenomena emerge. We are interested in both understanding the fundamentals of physical processes at small scales and exploiting emergent phenomena for new applications in sensing, separations and imaging. We have developed a number of electrode geometries and preparation methods, as well as hardware for measurement that afford the opportunity to probe small volumes at small scales. In Baker group, methods to fabricate multi-functional nanoelectrodes have been developed. For instance, parylene C and focused ion beam was used to fabricate nanoelectrodes of a variety of geometries for SICM-SECM imaging. Also, a ring/pore nanoelectrodes was utilized to study the influence of surface charge on nanopipette delivery. In addition, a strategy for electrode fabrication which utilizes gold and parylene coating to simultaneously perform topographic, conductance and electrochemical imaging was also developed. Representative electrodes images are shown below:
a) SEM micrograph of nanopipette-electrode with a clear distinction between the Au electrode (right), quartz (left) and parylene C insulation (top). b) SEM micrograph of a nanopipet tip with PANi ﬁlm on the surface of the AuE post electropolymerization. c) SEM micrograph of a carbon ring/nanopore electrode with an outer radius of 485 nm, inner radius of 295 nm, and nanopore dimensions of 440 nm (diameter).
A few publications related to electrochemistry in general are listed below.
Shi, W.; Sa, N.; Thakar, R.; Baker, L.A. Nanopipette Delivery: Influence of Surface Charge, Analyst, 2015, accepted. (http://dx.doi.org/10.1039/C4AN01073F).
Weber, A. E.; Shi, W.; Baker, L.A. Electrochemical Applications of Scanning Ion Conductance Microscopy. In Electroanalytical Chemistry; Bard, A.J., Zoski, C. Eds.; 2014, accepted
Sa, N.; Lan, W.; Shi, W.; Baker, L.A. Rectification of Ion Current in Nanopipettes by External Substrates, ACS Nano, 2013, 7, 11272–11282. (http://dx.doi.org/10.1039/c3an01216f).
Thakar, R.; Weber, A.E.; Morris, C.A.; Baker, L. A. Multifunctional Carbon Nanoelectrodes Fabricated by Focused Ion Beam Milling, Analyst, 2013, accepted. (http://dx.doi.org/10.1039/c3an01216f).
Zhou, Y.; Chen, C.C.; Weber, A.; Zhou, L.; Baker, L. A.; Hou, J. Potentiometric-Scanning Ion Conductance Microscopy for Measurement at Tight Junctions, Tissue Barriers, 2013, 1, e2558s. (https://www.landesbioscience.com/journals/tissuebarriers/article/25585/).
Morris, C.A.; Chen, C.; Ito, T.; Baker, L. A. Local pH Measurement with Scanning Ion Conductance Microscopy. J. Electrochem. Soc., 2013, 160, H430-H435. (http://dx.doi.org/10.1149/2.028308jes).
Sa, N.; Baker, L.A. Experiment and Simulation of Ion Transport through Nanopipettes of Well-defined Conical Geometry. J. Electrochem. Soc., 2013, 160, H376-H381. (http://dx.doi.org/10.1149/2.128306jes).
Chen, C.; Zhou, Y.; Morris, C.A.; Hou, J.; Baker, L.A. Scanning ion conductance microscopy measurement of paracellular conductance in tight junctions. Anal. Chem., 2013, 85, 3621-3628. (http://dx.doi.org/10.1021/ac303441n).
Morton, K.C.; Derylo, M.A.; Baker, L.A. Conductive Atomic Force Microscopy Probes from Pyrolyzed Parylene C. J. Electrochem. Soc., 2012, 159, H662-H667. (http://dx.doi.org/10.1149/2.061207jes).
Chen, C.; Zhou, Y.; Baker, L.A. Scanning Ion Conductance Microscopy. Annu. Rev. Anal. Chem., 2012, 5, 207-228. (http://dx.doi.org/10.1146/annurev-anchem-062011-143203).
Zhou, Y.; Chen, C.; Baker, L. A., Heterogeneity of Multiple-pore Membranes Investigated with Ion Conductance Microscopy. Anal. Chem., 2012, 84, 3003-3009. (http://dx.doi.org/10.1021/ac300257q).
Morris, C.A.; Chen, C.; Baker, L.A. Transport of Redox Probes through Single Pores Measured by Scanning Electrochemical-Scanning Ion Conductance Microscopy (SECM-SICM). Analyst, 2012, 137, 2933-2938. (http:// dx.doi.org/10.1039/C2AN16178H).
Basore, J.R.; Lavrik, N.V.; Baker, L.A. Magnetically Gated Microelectrodes. Chem. Comm., 2012, 48, 1009-1011. (http://dx.doi.org/10.1039/C2CC16938J).
Chen, C.; Zhou, Y.; Baker, L.A. Single nanopore investigations with ion conductance microscopy. ACS Nano, 2011, 5, 8404-8411 (http://dx.doi.org/10.1021/nn203205s).
Derylo, M.A.; Morton, K.C.; Baker, L.A. Parylene insulated probes for electrochemical atomic force microscopy. Langmuir, 2011, 27, 13925-13930 (http://dx.doi.org/10.1021/la203032u).
Sa, N.; Baker, L.A. Rectification of nanopores at surfaces. J. Am. Chem. Soc., 2011, 133, 10398-10401. (http://dx.doi.org/10.1021/ja203883q)
Morton, K. C.; Morris, C. A.; Derylo, M. A.; Thakar, R.; Baker, L. A. Carbon electrode fabrication from pyrolyzed parylene c. Anal. Chem., 2011, 83, 5447-5452. (http://dx.doi.org/10.1021/ac200885w).
Thakar, R.; Wilburn, J.; Baker, L. A. Studies of edge effects with shroud-modified electrodes. Electroanalysis, 2011, 23, 1543-1547. (http://dx.doi.org/10.1002/elan.201100170).