TY - JOUR
T1 - Pyrazinacene luminescence enhancement by heat-activated surface adsorption and de-aggregation in a saponite colloidal system
AU - Šuteková, Monika
AU - Barlog, Martin
AU - Baranyaiová, Tímea Šimonová
AU - Klement, Robert
AU - Richards, Gary J.
AU - Hill, Jonathan P.
AU - Labuta, Jan
AU - Bujdák, Juraj
N1 - Funding Information:
This work was supported by the Slovak Research and Development Agency under contract No. APVV-18-0075 and APVV-19-0487 , and by the VEGA agency ( 1/0227/20 , 2/0166/21 ). The authors are also grateful for support from World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan. The authors would like to thank Professor Róbert Mészáros from J. Selye University in Komárno (Slovakia) and Eötvös Loránd University (Budapest, Hungary) for his help, and providing useful comments and advice.
Funding Information:
This work was supported by the Slovak Research and Development Agency under contract No. APVV-18-0075 and APVV-19-0487, and by the VEGA agency (1/0227/20, 2/0166/21). The authors are also grateful for support from World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan. The authors would like to thank Professor R?bert M?sz?ros from J. Selye University in Kom?rno (Slovakia) and E?tv?s Lor?nd University (Budapest, Hungary) for his help, and providing useful comments and advice.
Publisher Copyright:
© 2022
PY - 2022/3/1
Y1 - 2022/3/1
N2 - This work presents heat-activated luminescence enhancement of butterfly-shaped pyrazinacene dye (BP) in an aqueous hybrid colloidal solution containing synthetic silicate, clay mineral saponite (Sap). The nitrogen-rich BP molecule consists of a quadruply benzo-fused fluorubine core N-alkylated at 6,13-positions with six hydrophilic [2-[2-(2-methoxyethoxy)ethoxy]ethoxy] chains to promote its solubility in polar solvents. BP exhibits strong luminescence emission especially in organic solvents. However, in aqueous solutions, BP dye alone usually aggregates, which leads to significantly weaker fluorescence. This effect can be overcome by using a mixed aqueous colloidal system containing Sap particles and BP dye molecules. This process is further promoted by heating the colloidal BP/Sap system to 70 °C, where the BP aggregates are irreversibly dispersed as monomers subsequently adsorbed at the surfaces of Sap particles. Following cooling to room temperature, the luminescence emission undergoes a several-fold increase in intensity. Such an improvement was not observed in aqueous solutions without the silicate or in hybrid colloids without thermal treatment. The heat-assisted irreversible adsorption of BP on Sap particles represents a simple stabilization method for fluorescence enhancement that can be applied to various other photoactive dyes in aqueous systems. This is essential to many applications, especially those involving biological systems, such as photosensitizers, luminescent sensors, or probes.
AB - This work presents heat-activated luminescence enhancement of butterfly-shaped pyrazinacene dye (BP) in an aqueous hybrid colloidal solution containing synthetic silicate, clay mineral saponite (Sap). The nitrogen-rich BP molecule consists of a quadruply benzo-fused fluorubine core N-alkylated at 6,13-positions with six hydrophilic [2-[2-(2-methoxyethoxy)ethoxy]ethoxy] chains to promote its solubility in polar solvents. BP exhibits strong luminescence emission especially in organic solvents. However, in aqueous solutions, BP dye alone usually aggregates, which leads to significantly weaker fluorescence. This effect can be overcome by using a mixed aqueous colloidal system containing Sap particles and BP dye molecules. This process is further promoted by heating the colloidal BP/Sap system to 70 °C, where the BP aggregates are irreversibly dispersed as monomers subsequently adsorbed at the surfaces of Sap particles. Following cooling to room temperature, the luminescence emission undergoes a several-fold increase in intensity. Such an improvement was not observed in aqueous solutions without the silicate or in hybrid colloids without thermal treatment. The heat-assisted irreversible adsorption of BP on Sap particles represents a simple stabilization method for fluorescence enhancement that can be applied to various other photoactive dyes in aqueous systems. This is essential to many applications, especially those involving biological systems, such as photosensitizers, luminescent sensors, or probes.
KW - Clay mineral
KW - Fluorescence
KW - Organic dye
KW - Saponite
KW - The hydrophobic effect
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UR - http://www.scopus.com/inward/citedby.url?scp=85122709985&partnerID=8YFLogxK
U2 - 10.1016/j.clay.2022.106413
DO - 10.1016/j.clay.2022.106413
M3 - Article
AN - SCOPUS:85122709985
SN - 0169-1317
VL - 218
JO - Applied Clay Science
JF - Applied Clay Science
M1 - 106413
ER -