Salicylimine-Based Fluorescent Chemosensor for Aluminum Ions and Application to Bioimaging

Abstract

In this study, an assay to quantify the presence of aluminum ions using a salicylimine-based receptor was developed utilizing turn-on fluorescence enhancement. Upon treatment with aluminum ions, the fluorescence of the sensor was enhanced at 510 nm due to formation of a 1:1 complex between the chemosensor and the aluminum ions at room temperature. As the concentration of Al(3+) was increased, the fluorescence gradually increased. Other metal ions, such as Na(+), Ag(+), K(+), Ca(2+), Mg(2+), Hg(2+), Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Pb(2+), Cr(3+), Fe(3+), and In(3+), had no such significant effect on the fluorescence. In addition, we show that the probe could be used to map intracellular Al(3+) distribution in live cells by confocal microscopy.

A new bifunctional Schiff base as a colorimetric and fluorescence sensor for Al3+ and CN−

“…S6). The observed fluorescent enhancement may be attributed to the formation of a rigid system after binding with Al 3+ , causing the chelation-enhanced fluorescence (CHEF) effect [28][29][30]. This unique selectivity of receptor 2 toward Al 3+ could be interpreted in terms of the smaller ionic radii and higher charge density of the Al 3+ ion.…”

A water-soluble carboxylic-functionalized chemosensor for detecting Al3+ in aqueous media and living cells: Experimental and theoretical studies

“…The substantial fluorescence enhancement of 1 might be explained by the restricted ESIPT (Wang et al, 2014) involving the phenolic protons (Scheme 1). Also, the selective fluorescence enhancement by Al 3 þ might be due to the effective coordination of Al 3 þ to 1, imparting the CHEF effect (Supriti et al, 2012;Kim et al, 2012).…”

“…A Schiff base, with π electrons in C ¼N group offers a good possibility for chelation with metal ions and can enhance the fluorescence through CHEF mechanism (Kim et al, 2012). In this regard, a julolidine moiety is a well-known chromophore and chemosensors with the julolidine moiety are usually water-soluble (Choi et al, 2014).…”

Development of a simple pyrazine-derived “turn on” Al 3+ fluorescent sensor with high selectivity and sensitivity

“…Aluminum is regarded as a toxic element, because Al 3+ can cause damage to central nervous system and immune system in human bodies [18], affecting the absorb and use of other trace elements [19], and induce many health problems, such as Alzheimer's disease and Parkinson's disease [20]. Nevertheless, there have been only a few reports about the development of fluorescent chemosensors for Al 3+ because of its poor coordination ability [21]. Therefore, it is a great demand to design and synthesize Al 3+ selective and sensitive fluorescent chemosensors [22][23][24][25][26].…”