• 한국환경과학회지
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• 제32권11호
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• pp.757-765
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• 2023

Lead, a heavy metal widely employed in various industries, continues to pose a threat to both human health and the environment. Therefore, the development of a sensor capable of rapidly and accurately detecting lead(II) ions in real-time at contaminated sites is crucial. In this study, we have engineered a fluorescent sensor with the ability to efficiently detect lead(II) ions under actual environmental conditions, including tap water and freshwater. The compound, tetraphenylethylene carboxylic acid derivative (TPE-COOH), exhibits high selectivity and sensitivity toward lead(II) ions in aqueous solution, where the interaction between TPE-COOH and lead(II) ions leads to its aggregation, thus triggering a fluorescence "turn-on" based on the aggregation-induced emission (AIE) mechanism. Impressively, compound TPE-COOH proficiently detects lead(II) ions within a range of 30 to 100 𝜇M in tap water and freshwater, even in the presence of various interfering substances.

• 대한방사성의약품학회지
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• 제9권2호
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• pp.57-61
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• 2023

In this research, novel AIE (Aggregation-Induced Emission) fluorophores were synthesized by ingeniously attaching a variety of substituents, including allyl, benzyl, and propargyl groups, to the hydroxy and carboxylate groups of fluorescein. The findings revealed a fascinating trend: the fluorescence intensity of these compounds varied progressively with the solvent ratio. This intriguing behavior is attributed to the superior aggregation of the synthesized materials in aqueous environments compared to organic solvents, resulting in markedly enhanced fluorescence. Moreover, the optical characteristics of these materials were found to be significantly influenced by the specific type of substituent grafted onto the fluorescein backbone. Notably, the fluorescence intensity was observed to escalate in the sequence of methoxy triethylene glycol, azidoethyl, allyl, propargyl, and benzyl group in the solution of H2O:DMSO (=99:1). The implications of this study can be vast, particularly in the realm of fundamental research areas like molecular imaging and sensor technology. These innovative AIE fluorophores offer a promising platform for advanced applications, leveraging their unique fluorescence behavior dictated by the nature of the substituent and the solvent environment.

• 센서학회지
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• 제15권5호
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• pp.303-308
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• 2006

Aggregation-induced emissions of polymetalloles have been investigated since they are very attractive in their possible optoelectronic applications such as P-LED's and Sensors. Size of nanoparticulates was measured by using scanning electron micrograph and was about 200-300 nm. Phenylmethylpolysilane (PMPS) and polymetalloles emit the light at 360 nm and 520 nm, respectively. However, the aggregates of polymetallole containing PMPS exhibit an enhanced emission band at 520 nm, indicating that the energy transfer occurs from PMPS to polymetalloles in aggregates. Emission intensity of PMPS/polymetallole nanoparticulates at 520 nm increases depending on the aliquot of PMPS.

• Bulletin of the Korean Chemical Society
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• 제27권12호
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• pp.1965-1966
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• 2006

• Bulletin of the Korean Chemical Society
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• 제26권10호
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• pp.1555-1559
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• 2005

High-performance fluorescent probes which exhibit either on/off or dual color fluorescence switching in response to the presence of organic vapors with a rapid response, a high sensitivity and a high-contrast on/off signaling ratio were demonstrated on the basis of the vapor-controlled AIEE phenomenon.

• 대한방사성의약품학회지
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• 제6권2호
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• pp.116-130
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• 2020

The aging society is globally one of biggest issue because it is related with various degenerative brain disease such as dementia, Parkinson's disease, Alzheimer's disease, multiple sclerosis, and cerebrovascular disease. These diseases are characterized by misfolded-protein aggregation; another pathological trait is "neuroinflammation". In physiological state, the resting microglia cells are activated and it removes abnormal synapses and cell membrane debris to maintain the homeostasis. In pathological state, however, microglia undergo morphological change form 'resting' to 'activated amoeboid phenotype' and the microglia cells are accumulated by neuronal damage, the inflammatory reactions induced nerve metamorphosis with a variety of neurotoxic factors including cytokines, chemokines, and reactive oxygen species. Thus, the activated microglia cell with various receptors (TSPO, COX, CR, P2XR, etc.) was perceived as important biomarkers for imaging the inflammatory progression. In this review, we would like to introduce the current status of the development of radiotracers that can image activated microglia.

• Molecules and Cells
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• 제21권2호
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• pp.229-236
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• 2006

Gaegurin 4 (GGN4), a novel peptide isolated from the skin of a Korean frog, Rana rugosa, has broad spectrum antimicrobial activity. A number of amphipathic peptides closely related to GGN4 undergo a coil to helix transition with concomitant oligomerization in lipid membranes or membrane-mimicking environments. Despite intensive study of their secondary structures, the oligomeric states of the peptides before and after the transition are not well understood. To clarify the structural basis of its antibiotic action, we used analytical ultracentrifugation to define the aggregation state of GGN4 in water, ethyl alcohol, and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP). The maximum size of GGN4 in 15% HFIP corresponded to a decamer, whereas it was monomeric in buffer. The oligomeric transition is accompanied by a cooperative 9 nm blue-shift of maximum fluorescence emission and a large secondary structure change from an almost random coil to an ${\alpha}$-helical structure. GGN4 induces pores in lipid membranes and, using electrophysiological methods, we estimated the diameter of the pores to be exceed $7.3{\AA}$, which suggests that the minimal oligomer structure responsible is a pentamer.