Department of Materials Science and Engineering, Kookmin Univ.
Hyunho Jung (MS candidate)
Fluorescence Enhancement from Nitro-Compound-Sensitive Bacteria within Spherical Hydrogel Scaffolds Chemical sensors are devices that can convert a chemical and physical signal by an analytic one. The chemical signal is created through a selective interaction between a sensing material placed in the sensor and a target analyte (or sensing moieties), and each chemical sensor consists of a sensing element and a transducer. In our lab, we are focusing on the biocompatible and biodegradable materials-based sensors for explosive compounds or E-coli or hazardous gas detection. Recently, the fluorescence sensor based on hydrogels has been utilized to detect nitro-compounds. Hydrogel_based sensors are applied for monitoring food putrefaction or fermentation. |
Food Sensor Based on Hydrogel for Low-Concentration Detection of Ammonia With the increasing market share of ready-to-cook foods, accurate determination of the food freshness and thus food safety has emerged as a concern. To commercialize and popularize food sensing technologies, food sensors with diverse functionalities, low cost, and facile use must be developed. This paper proposes printable sensors based on a hydrogel-containing pH indicator to detect ammonia gas. The sensors were composed of biocompatible polymers such as 2-hydroxyethyl methacrylate (HEMA) and [2-(methacryloyloxy)ethyl] trimethylammonium chloride (MAETC). The p(HEMA-MAETC) hydrogel sensor with bromothymol blue (BTB) demonstrated visible color change as a function of ammonia concentration during food spoilage. Furthermore, polyacrylonitrile (PAN) was added to improve transport speed of ammonium ions as the matrix in the sensors and optimized the viscosity to enable successful printing. The color changed within 3 min at ammonia concentration of 300 ppb and 1 ppm, respectively. The sensor exhibited reproducibility over 10 cycles and selective exposure to various gases generated during the food spoilage process. In an experiment involving pork spoilage, the color change was sig-nificant before and after exposure to ammonia gas within 8 h in ambient conditions. The proposed sensor can be integrated in bar codes and QR codes that are easily mass produced. Cover images for hydrogel sensors |
Relevent Publication
1 | Soohyun Kim, Hyunji Kim, Tian Qiao, Chaenyung Cha, Sung Kuk Lee, Kangseok Lee, Hyun Ji Ro, Youngkyun Kim, Wonmok Lee, Hyunjung Lee*,\"Fluorescence Enhancement from Nitro-Compound-Sensitive Bacteria within Spherical Hydrogel Scaffolds.\" ACS applied materials & interfaces , 2019, 11.15: 14354-14361. |
2 | Tian Qiao, Soohyun Kim, Wonmok Lee, and Hyunjung Lee*, “Biodegradable and Porous Poly(lacticco-glycolic acid) Microbeads for In vitro Evaluation of Negatively Charged Fluorescent Bacteria”, Macromolecular Research, 2019, 27.3: 321-326 |
3 | Seulki Kim, Sung Gu Han, Young Gook Koh, Hyunjung Lee and Wonmok Lee*, “Colorimetric Humidity Sensor Using Inverse Opal Photonic Gel in Hydrophilic Ionic Liquid”, Sensors 2018, 18, 1357 |
4 | Kangseok Lee, Jisu Hong, Hyun Ji Roh, Soo Hyun Kim, Hyunjung Lee, Sung Kuk Lee, Chaenyung Cha*; “Dual ionic crosslinked interpenetrating network of alginate-cellulose beads with enhanced mechanical properties for biocompatible encapsulation”, Cellulose, 2017, 24(11), 4963–4979 |
5 | Hwanam Kye, Young Gook Koh, Youkyung Kim, Sung Gu Han, Hyunjung Lee*, and Wonmok Lee*, “Tunable Temperature Response of a Thermochromic Photonic Gel Sensor Containing N-Isopropylacrylamide and 4-Acryloyilmorpholine”, Sensors 2017, 17, 1398 |