Fluorescence enhancement mechanism of thymolphthalein-based probe by coordination interaction with zinc ion

A new water-soluble ligand bearing a tetrasulfonated calix[4]arene was constructed for ratiometric detection of Al3+ based on an aggregation-induced fluorescence enhancement mechanism.

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Surface-Enhanced Raman Scattering and Fluorescence on Gold Nanogratings

Nanomaterials ◽

10.3390/nano10040776 ◽

2020 ◽

Vol 10 (4) ◽

pp. 776 ◽

Cited By ~ 2

Author(s):

Yu-Chung Chang ◽

Bo-Han Huang ◽

Tsung-Hsien Lin

Keyword(s):

Thin Film ◽

Raman Scattering ◽

Fluorescence Enhancement ◽

Surface Enhanced Raman Scattering ◽

Simple Method ◽

Enhancement Mechanism ◽

Gold Thin Film ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Enhanced Raman Scattering

Surface-enhanced Raman scattering (SERS) spectroscopy is a sensitive sensing technique. It is desirable to have an easy method to produce SERS-active substrate with reproducible and robust signals. We propose a simple method to fabricate SERS-active substrates with high structural homogeneity and signal reproducibility using electron beam (E-beam) lithography without the problematic photoresist (PR) lift-off process. The substrate was fabricated by using E-beam to define nanograting patterns on the photoresist and subsequently coat a layer of gold thin film on top of it. Efficient and stable SERS signals were observed on the substrates. In order to investigate the enhancement mechanism, we compared the signals from this substrate with those with photoresist lifted-off, which are essentially discontinuous gold stripes. While both structures showed significant grating-period-dependent fluorescence enhancement, no SERS signal was observed on the photoresist lifted-off gratings. Only transverse magnetic (TM)-polarized excitation exhibited strong enhancement, which revealed its plasmonic attribution. The fluorescence enhancement showed distinct periodic dependence for the two structures, which is due to the different enhancement mechanism. We demonstrate using this substrate for specific protein binding detection. Similar periodicity dependence was observed. Detailed theoretical and experimental studies were performed to investigate the observed phenomena. We conclude that the excitation of surface plasmon polaritons on the continuous gold thin film is essential for the stable and efficient SERS effects.

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A Novel Thiophene-Based Fluorescent Chemosensor for the Detection of Zn2+ and CN−: Imaging Applications in Live Cells and Zebrafish

Sensors ◽

10.3390/s19245458 ◽

2019 ◽

Vol 19 (24) ◽

pp. 5458 ◽

Cited By ~ 3

Author(s):

Min Seon Kim ◽

Dongju Yun ◽

Ju Byeong Chae ◽

Haeri So ◽

Hyojin Lee ◽

...

Keyword(s):

Hela Cells ◽

Fluorescence Enhancement ◽

Limit Of Detection ◽

Zinc Ion ◽

World Health ◽

Live Cells ◽

Real Samples ◽

Turn On ◽

Health Organization ◽

Nmr Titrations

A novel fluorescent turn-on chemosensor DHADC ((E)-3-((4-(diethylamino)-2-hydroxybenzylidene)amino)-2,3-dihydrothiophene-2-carboxamide) has been developed and used to detect Zn2+ and CN−. Compound DHADC displayed a notable fluorescence increase with Zn2+. The limit of detection (2.55 ± 0.05 μM) for zinc ion was far below the standard (76 μM) of the WHO (World Health Organization). In particular, compound DHADC could be applied to determine Zn2+ in real samples, and to image Zn2+ in both HeLa cells and zebrafish. Additionally, DHADC could detect CN− through a fluorescence enhancement with little inhibition with the existence of other types of anions. The detection processes of compound DHADC for Zn2+ and CN− were demonstrated with various analytical methods like Job plots, 1H NMR titrations, and ESI-Mass analyses.

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