Volume 36, Issue 1

Recently, numerous luminescent molecular thermometers that exhibit temperature-dependent emission properties have been developed to measure the temperatures of tiny spaces. Intracellular temperature is the most interesting and exciting applications of luminescent molecular thermometers because this temperature is assumed to be correlated with all cell events, such as cell division, gene expression, enzyme reaction, metabolism, and pathogenesis. Among the various types of temperature-dependent emission parameters of luminescent molecular thermometers, the emission intensity ratio at two different wavelengths is suitable for accurate and accessible intracellular temperature measurements. In this review article, luminescent molecular thermometers that exhibit a temperature-dependent emission intensity ratio in living cells are summarized, and current progress in intracellular thermometry is outlined.

Dysregulation of gene expression mechanisms has been observed in many tumors, making their analysis of utmost importance. These mechanisms include DNA methylation, an epigenetic mechanism in which 5-carbon of cytosine becomes methylated, leading to gene silencing, and action of short RNA molecules called microRNAs, which regulate protein synthesis at post-transcriptional level by binding to mRNAs. In this review, we describe major roles of both mechanisms in carcinogenesis, offer an overview of currently used methods for their analysis, and summarize most recent advances in electrochemical-based assays and strategies. Advantages of electrochemistry, including favorable cost, time of experiment, or simple instrumentation, are highlighted, along with current challenges that need to be addressed prior to successful application into clinical routine.

Surface-enhanced Raman spectroscopy (SERS) is a highly promising analytical technique that has been widely applied in health and environment monitoring. As a vibrational spectroscopic tool, its fingerprint spectrum contains abundant molecular information, and the greatly enhanced signal can be used to detect analytes at extremely low concentration, even down to the single molecule level. Because water molecules give very weak Raman response, Raman spectroscopy has also been applied for in situ monitoring of targets in solution. However, the Raman signal of an analyte could only be enhanced when it is in proximity to the SERS substrate, which enhances the signal depending on the shape, size, and orientation of the particles constituting the substrate. Further, when using the method for the detection of various analytes, it is necessary to functionalize the SERS substrates, with recognition ligands and encapsulation with a suitable shell among others. Hence, the fabrication of suitable substrates is a basic step in SERS-related research. Tremendous effort has been expended in the last decade in this area, resulting in the development of substrates with unique properties. In this review, we will introduce recent achievements in SERS substrate fabrication based on their structural features. Synthesized nanoparticles, two-dimensional planar substrates, and three-dimensional substrates with effective volume will be discussed in the context of their synthesis strategies along with their characteristic properties. In the future, with further improvement in SERS substrates, the applicability of SERS for detecting a range of analytes in complex environment will become possible.