Nanomaterials for IoT Sensing Platforms and Point-of-Care Applications in South Korea

Herein, state-of-the-art research advances in South Korea regarding the development of chemical sensing materials and fully integrated Internet of Things (IoT) sensing platforms were comprehensively reviewed for verifying the applicability of such sensing systems in point-of-care testing (POCT). Various organic/inorganic nanomaterials were synthesized and characterized to understand their fundamental chemical sensing mechanisms upon exposure to target analytes. Moreover, the applicability of nanomaterials integrated with IoT-based signal transducers for the real-time and on-site analysis of chemical species was verified. In this review, we focused on the development of noble nanostructures and signal transduction techniques for use in IoT sensing platforms, and based on their applications, such systems were classified into gas sensors, ion sensors, and biosensors. A future perspective for the development of chemical sensors was discussed for application to next-generation POCT systems that facilitate rapid and multiplexed screening of various analytes.

Characteristics of Ultrasensitive Hexagonal-Cored Photonic Crystal Fiber for Hazardous Chemical Sensing

A highly sensitive non-complex cored photonic crystal fiber sensor for hazardous chemical sensing with water, ethanol, and benzene analytes has been proposed and is numerically analyzed using a full-vector finite element method. The proposed fiber consists of a hexagonal core hole and two cladding air hole rings, operating in the lower operating wavelength of 0.8 to 2.6 µm. It has been shown that the structure has high relative sensitivity of 94.47% for water, 96.32% for ethanol and 99.63% for benzene, and low confinement losses of 7.31 × 10−9 dB/m for water, 3.70 × 10−10 dB/m ethanol and 1.76 × 10−13 dB/m benzene. It also displays a high power fraction and almost flattened chromatic dispersion. The results demonstrate the applicability of the proposed fiber design for chemical sensing applications.

A Versatile Terahertz Chemical Microscope and Its Application for the Detection of Histamine

Terahertz waves have gained increasingly more attention because of their unique characteristics and great potential in a variety of fields. In this study, we introduced the recent progress of our versatile terahertz chemical microscope (TCM) in the detection of small biomolecules, ions, cancer cells, and antibody–antigen immunoassaying. We highlight the advantages of our TCM for chemical sensing and biosensing, such as label-free, high-sensitivity, rapid response, non-pretreatment, and minute amount sample consumption, compared with conventional methods. Furthermore, we demonstrated its new application in detection of allergic-related histamine at low concentration in buffer solutions.

Solvent and Substituent Effect on Selectivity of Triphenylether-Based Ionophores: A Voltammetric Study

The past two decades have seen considerable attention given to chemical sensing due to its quick, reproducible, and accurate results. These are extensively used for the detection of cations and anions in different environmental matrices. Organic-molecule-based sensors have proved to be a great promising tool in determining target species. This communication demonstrates the use of triphenylether derivatives (L1–L4) as receptors for the sensing of cations and anions, using voltammetry as a sensing tool. The effect of the oxidative/reductive nature of the ionophores and, hence, their selectivity behavior was studied in MeCN and MeOH solvents. Three receptors (L2–L4) responded selectively towards cyanide ions following the intramolecular charge-transfer mechanism, while sensing in the case of L1 was not studied because it lacked a proper cavity size.