Synthesis and Sensor Activity of a PET-based 1,8-naphthalimide Probe for Zn2+ and pH Determination

Abstract

A novel blue-emitting 1,8-naphthalimide fluorophore designed as a molecular PET-based probe for determination of pH and detection of transition metal ions in the environment was successfully synthesized. Novel compound was configured on the "fluorophore-spacer-receptor" format. Due to the tertiary amine receptor the novel system showed "off-on" switching properties under the transition from alkaline to acid media (FE = 3.2) and in the presence of Zn(2+) ions (FE = 2.5). The results obtained illustrate the high potential of the synthesized blue-emitting 1,8-naphthalimide fluorophore as an efficient pH chemosensing material and a selective probe for Zn(2+) ions.

Sensitive and selective detection of Cu(II) ion: A new effective 1,8‐naphthalimide‐based fluorescence ‘turn off’ sensor

“…Synthesis of compound II was carried out using a slight modification of a previously reported procedure in which 2.85 ml (0.05 mol) of allyl amine mixed with 100 ml of ethanol was added to 13.85 g (0.05 mol) of 4‐bromo‐1,8‐naphthalimide (compound I, obtained from a commercial supplier) dissolved in 150 ml of ethanol. The reaction mixture was subjected to reflux in a water bath for 4–5 h with the temperature maintained at 60°C.…”

“…Accordingly, there has been many applications of 1,8‐naphthalimide derivatives as components of liquid crystal displays, laser active medium, fluorescent markers in biology, photoinduced electron transfer chemosensors, electroluminescence devices and fluorescence switchers and probes . Ester, amino and carboxyl group‐terminated 1,8‐naphthalimide fluorophores have previously been synthesized and studied …”

A “weak acid and weak base” type fluorescent probe for sensing pH: mechanism and application in living cells

“…[31][32][33] Therefore, they have great potential for developing uorescent probes. [34][35][36][37] Here, we report a 1,8-naphthalimide derivative, Naphthalimideisoniazid hybrid NDI as a new pH-sensitive probe with a suitable pK a 1 (4.50) and pK a 2 (9.34) for biosystem investigation. This probe can respond to an acidic pH range from 3.00 to 6.50 and an alkaline pH range from 8.30 to 10.50 with an excellent linear relationship.…”

Synthesis, chemosensing properties and logic behaviour of a novel ratiometric 1,8-naphthalimide probe based on ICT and PET

“…Two common principles for fluorescence molecular switches are used: photoinduced electron transfer (PET) and internal charge transfer (ICT) [15][16][17][18]. PET regularly occurs when certain organic systems interact with light, and the format of "fluorophore-spacer-receptor" is the most commonly exploited approach for the design of fluorescent sensors and switches [19][20][21][22]. The fluorophore is covalently linked to a receptor with a non-π-electron-conjugating spacer group (usually alkyl group with two carbons).…”