**Preface to "Bioelectric Sensors"**

Bioelectric sensors represent a continuously growing segmen<sup>t</sup> of biosensor technologies and applications, offering key advantages in terms of their practicability of application and scalability of manufacturing. Progress in related fields has been considerably boosted by advances in microelectronics and nanotechnology, in general, while the quiver of biocompatible materials serving as intermediates between biorecognition elements and electronic components has been impressively expanded. Although bioelectric sensors share many traits with electrochemical sensors, especially regarding common features of instrumentation, they are focused on the measurement of the electric properties of biorecognition elements as a reflection of cellular, biological, and biomolecular functions in a rapid, very sensitive, and often non-invasive manner. Bioelectric sensors offer a plethora of options in terms both of assay targets (molecules, cells, organs, and organisms) and methodological approaches (e.g., potentiometry, impedance spectrometry, patch-clamp electrophysiology). Irrespective of the method of choice, "bioelectric profiling" is being rapidly established as a superior concept for several applications, including in vitro toxicity, signal transduction, real-time medical diagnostics, environmental risk assessment, and drug development.

The Special Issue *Bioelectric Sensors* is the first one exclusively dedicated to advanced and emerging concepts and technologies of bioelectric sensors. Contributed articles focus on key topics such as reflectance-based pulse sensors, wireless monitoring systems, and bioelectric biochips and applications including non-invasive wound healing, cancer cell fingerprinting, differential drug screening, and advanced pacemaker performance modeling. All approaches are handled in the context of point-of-care/portable and wireless instrumentation and intelligent bioelectric sensing platforms.

> **Spyridon Kintzios** *Editor*
