Zinc‐Ion‐Induced Aggregation of Gold Clusters for Visible‐Light‐Excitation‐Based Fluorimetric Discrimination of Geometrical Isomers

Abstract

Herein, we report discrimination of dicarboxylic acids -fumaric acid (FA) and maleic acid (MA) -exhibiting geometrical isomerism, using nanoclusters based luminescent probe having excitation under broad day light. The luminescent probe was designed via complexation reaction between zinc ions and ligands (mercaptopropioinc acid; MPA) stabilizing the gold nanoclusters. This resulted in formation of nanoaggregates exhibiting bright green luminescence upon excitation at 450 nm capable of discriminating between FA and MA upto nanomolar level. The basis of discrimination has been attributed to deprotonation of FA and MA following interaction with MPA moieties present on the surface of the nanoaggregates and being governed by the stability of the respective conjugate base of the geometrical isomers of the dicarboxylic acids. As a consequence of different extent of deprotonation of FA and MA upon interaction with the cluster aggregates, different effect on the luminescence of the aggregates was observed, thus enabling discernible fluorimetric discrimination between FA and MA under visible light excitation.[a] Dr.

Aggregation induced delayed green fluorescence from assembly of gold nanoclusters: an advanced probe for “background free” pyrophosphate recognition

“…Recently, metal ion-induced aggregation of atomic clusters has been reported to be widely used for sensing (and imaging) of a plethora of analytes. [26][27][28][29][30][31][32][33][34] Thus, harnessing the delayed fluorescence properties of atomic clusters via chemical reaction-based aggregation may emerge to be an interesting avenue towards fabrication of newer optical materials.…”

Self‐Assembly of Precision Noble Metal Nanoclusters: Hierarchical Structural Complexity, Colloidal Superstructures, and Applications

“…A similar strategy was used to demonstrate the assembled frameworks from various NCs. [ 320–328 ] Among them, a few found interesting applications. For example, the assembled superstructures fabricated from [Au 14 (MPA) 7 (His) 5 ] [ 320 ] and [Au 14 (MPA) 10 (Phe) 4 ] 3+[ 321 ] (MPA = mercaptopropionic acid; His = l ‐histidine; Phe = l ‐phenyl alanine) NCs have been successfully used to demonstrate the gas storage (details are provided in Section 4).…”

Assembling Atomically Precise Noble Metal Nanoclusters Using Supramolecular Interactions

“…Recently, the rapid and cyclic detection of explosives such as nitrobenzene (NB) was performed using a hybrid polymer membrane generated from [Ag 12 (StBu) 6 (CF 3 COO) 6 (NH 2 -bpz) 3 ] n -MOF [NH 2 -Ag 12 bpz] . The chiral recognition of d - and l -Trp (Trp = tryptophan) was reported using the assembled enantiomeric [Au 14 (MPA) 6 ( d / l -Trp) 4 ] NMNCs generated by Zn 2+ coordination (MPA = 3-mercaptopropionic acid) …”

“…Various applications of supramolecular complexes of NMNCs are pointed out in the following: 93 The chiral recognition of Dand L-Trp (Trp = tryptophan) was reported using the assembled enantiomeric [Au 14 (MPA) 6 (D/L-Trp) 4 ] NMNCs generated by Zn 2+ coordination (MPA = 3-mercaptopropionic acid). 94…”

“… 93 The chiral recognition of d - and l -Trp (Trp = tryptophan) was reported using the assembled enantiomeric [Au 14 (MPA) 6 ( d / l -Trp) 4 ] NMNCs generated by Zn 2+ coordination (MPA = 3-mercaptopropionic acid). 94 …”