Electrochemical Sensors and Biosensors

This review covers advances in electrochemical and biochemical sensor development and usage during 2010 and 2011. In choosing scholarly articles to contribute to this review, special emphasis was placed on work published in the areas of reference electrodes, potentiometric sensors, voltammetric sensors, amperometric sensors, biosensors, immunosensors, and mass sensors. In the past two years there have been a number of important papers, that do not fall into the general subsections contained within the larger sections. Such novel advances are very important for the field of electrochemical sensors as they open up new avenues and methods for future research. Each section above contains a subsection titled “Other Papers of Interest” that includes such articles and describes their importance to the field in general. For example, while most electrochemical techniques for sensing analytes of interest are based on the changes in potential or current, Shan et al.1 have developed a completely novel method for performing electrochemical measurements. In their work, they report a method for imaging local electrochemical current using the optical signal of the electrode surface generated from a surface plasmon resonance (SPR). The electrochemical current image is based on the fact that the current density can be easily calculated from the local SPR signal. The authors demonstrated this concept by imaging traces of TNT on a fingerprint on a gold substrate. Full articles and reviews were primarily amassed by searching the SciFinder Scholar and ISI Web of Knowledge. Additional articles were found through alternate databases or by perusing analytical journals for pertinent publications. Due to the reference limitation, only publications written in English were considered for inclusion. Obviously, there have been more published accounts of groundbreaking work with electrochemical and biochemical sensors than those covered here. This review is a small sampling of the available literature and not intended to cover every advance of the past two years. The literature chosen focuses on new trends in materials, techniques, and clinically relevant applications of novel sensors. To ensure proper coverage of these trends, theoretical publications and applications of previously reported sensor development were excluded. We want to remind our readers that this review is not intended to provide comprehensive coverage of electrochemical sensor development, but rather to provide a glimpse of the available depth of knowledge published in the past two years. This review is meant to focus on novel methods and materials, with a particular focus on the increasing use of graphene sheets for sensor material development. For readers seeking more information on the general principles behind electrochemical sensors and electrochemical methods, we recommend other sources with a broader scope.2, 3 Electrochemical sensor research is continually providing new insights into a variety of fields and providing a breadth of relevant literature that is worthy of inclusion in this review. Unfortunately, it is impossible to cover each publication and unintentional oversights are inevitable. We sincerely apologize to the authors of electrochemical and biochemical sensor publications that were inadvertently overlooked.