A New, Highly Potent 1,8‐Naphthalimide‐based Fluorescence “Turn off” Chemosensor Capable of Cu²⁺ Detection in China's Yellow River Water Samples

Abstract

A new 1,8‐naphthalimide‐based fluorescence “turn off” chemosensor, N‐phenyl‐4‐(3,3′‐((2‐aminoethyl)azanediyl)dipropanoic acid)‐1,8‐naphthalimide (MAST), for the detection of Cu2+ was synthesized. Upon treatment with Cu2+, in coexistence with various competitive metal ions in HEPES‐buffered dimethylsulfoxide (DMSO) solution (v/v, 1:1; pH 7.4), MAST displayed a high selectivity toward Cu2+ with a fluorescence quenching of 83.67%. Additionally, a good linear response of MAST for the detection of Cu2+ was obtained in the concentration range of 10 × 10−6 to 50 × 10−6 M. A 1:1 stoichiometric interaction of MAST with Cu2+ was observed, and the association constant and detection limit were calculated to be 1.37 × 106 and 0.69 × 10−8 M, respectively. The sensing mechanism of the chemosensor toward Cu2+ was proposed due to the effect of the paramagnetic nature of Cu2+ and reverse‐photo‐induced electron transfer (PET) process. Ultimately, the proposed chemosensor was applied to quantify Cu2+ in real‐world water samples, with excellent recovery rates of 98.00–109.80% observed.

BODIPY Immobilized MCM‐41 Based Multianalyte Sensor: Application in Detection and Removal of Trivalent (Al3+, Cr3+) and Divalent (Cu2+, Hg2+) Metal Ions in Aqueous Media

“…Due to the protonation of À NH, the involvement of lone pair of electrons on the nitrogen atom towards the BODIPY core will be restricted (PET OFF), thereby increasing the emission. [86] Contrary to this, in basic pH the À NH will deprotonate and the negatively charged nitrogen atom triggers the movement of electrons towards the BODIPY core resulting in the decrease of the emission intensity (PET ON). [85] Therefore, MS4 was used within the pH range of 4-10 for the detection of Al 3 + , Cr 3 + , Cu 2 + and Hg 2 + metal ion, as shown in Figure S31.…”