Fluorescent carbon dots and noble metal nanoclusters for sensing applications: Minireview

Abstract

Nanomaterial‐based fluorescence sensing systems with the advantages of sensitivity and selectivity have been popular for quantitation of various analytes, including biomolecules, metal ions, and organic molecules. Fluorescent carbon dots (C dots) and noble metal nanoclusters (MNCs) separately composed of few carbon and metal atoms have attracted considerable research interest in the past decade, mainly because of their biocompatibility, as well as ease in preparation and conjugation. This review briefly discusses simple and popular strategies for the preparation of C dots and MNCs. Their sensing applications in monitoring pH values, quantitation of metal ions, and small molecules are emphasized. Their future use in conjunction with portable microsystems such as array and microfluidic device to develop high‐throughput and sensitive sensing systems for on‐site analysis is also discussed.

Enzyme-mimic catalytic activities and biomedical applications of noble metal nanoclusters

“…56 Similar to organic molecules, they can be synthesized at atomic precision and with known step reaction pathways. 57,58 Until now, many synthetic methods have been documented to deliver the desired purity and quantity for selected metal NCs, 59–61 such as Brust-Schiffrin, 62 two-phase, 63 and seeded growth methods 64 and so on. These methods can be classified into three types: bottom-up synthesis, top-down synthesis, and inter-cluster conversion, according to the formation pathways of metal NCs.…”

Chiroptically active copper clusters as platform for enantioselective detection of lysine

“…17,18 The alterations in chiral absorption efficiency as well as emission profile arising due to the surface modification can be leveraged for sensing purposes. [19][20][21][22][23] Among the different metals employed for the synthesis of nanoclusters, copper shows significant promise over other counterparts such as gold and silver, due to its cost-effectiveness and abundant availability. [24][25][26] Herein, we present the chiral enantiomeric detection of lysine utilizing a pair of optically active copper clusters.…”

“…These nanostructures exhibit high sensitivity to its environment, rendering them excellent candidates for sensing applications 17,18 . The alterations in chiral absorption efficiency as well as emission profile arising due to the surface modification can be leveraged for sensing purposes 19–23 . Among the different metals employed for the synthesis of nanoclusters, copper shows significant promise over other counterparts such as gold and silver, due to its cost‐effectiveness and abundant availability 24–26 .…”

Facile one‐pot synthesis of PEG‐derived carbon dots with enhanced luminescence via L‐cysteine‐assisted S,N‐doping

“…Carbon Nanodots are among the interesting photoluminescent nanomaterials (e.g., metal nanoclusters, quantum dots, rare earth, etc.) [1][2][3][4][5][6][7] which have the potential to replace fluorescent dyes in biomedical fields, especially for biosensing and bioimaging [8][9][10][11][12]. This projection is because of the fact that carbon dots can be produced utilizing inexpensive carbon sources and, most importantly, have excellent photoluminescence stability, in contrary to fluorescent dyes that have photobleaching issues [12][13][14][15].…”