Details

Autor(en) / Beteiligte

• Sarkar, Krishanu
• Dhara, Koushik
• Nandi, Mahasweta
• Roy, Partha
• Bhaumik, Asim
• Banerjee, Pradyot

Titel

Selective Zinc(II)‐Ion Fluorescence Sensing by a Functionalized Mesoporous Material Covalently Grafted with a Fluorescent Chromophore and Consequent Biological Applications

Ist Teil von

• Advanced functional materials, 2009-01, Vol.19 (2), p.223-234

Ort / Verlag

Weinheim: WILEY‐VCH Verlag

Erscheinungsjahr

2009

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• A highly ordered 2D‐hexagonal mesoporous silica material is functionalized with 3‐aminopropyltriethoxysilane. This organically modified mesoporous material is grafted with a dialdehyde fluorescent chromophore, 4‐methyl‐2,6‐diformyl phenol. Powder X‐ray diffraction, transmission electron microscopy, N2 sorption, Fourier transform infrared spectroscopy, and UV‐visible absorption and emission have been employed to characterize the material. This material shows excellent selective Zn2+ sensing, which is due to the fluorophore moiety present at its surface. Fluorescence measurements reveal that the emission intensity of the Zn2+‐bound mesoporous material increases significantly upon addition of various concentrations of Zn2+, while the introduction of other biologically relevant (Ca2+, Mg2+, Na+, and K+) and environmentally hazardous transition‐metal ions results in either unchanged or weakened intensity. The enhancement of fluorescence is attributed to the strong covalent binding of Zn2+, evident from the large binding constant value (0.87 × 104 M−1). Thus, this functionalized mesoporous material grafted with the fluorescent chromophore could monitor or recognize Zn2+ from a mixture of ions that contains Zn2+ even in trace amounts and can be considered as a selective fluorescent probe. We have examined the application of this mesoporous zinc(II) sensor to cultured living cells (A375 human melanoma and human cervical cancer cell, HeLa) by fluorescence microscopy. Selective Sensing: A dialdehyde fluorophore has been grafted over highly ordered 2D‐hexagonal mesoporous silica, and the resulting mesoporous material shows unique sensing for zinc(II) in trace amounts together with a drastic enhancement in fluorescence intensity (see figure). Fluorescence imaging (figure inset) allows the intracellular Zn2+ concentration to be monitored when cultured living cells (A375 human melanoma and HeLa cells) are incubated with the functionalized silica.