Green Synthesis of Carbon Dot Weak Gel from Pear Juice: Optical Properties and Sensing Application

Abstract

Herein, we report for the first time a low-cost and eco-friendly carbon dot weak gel (CDWG) in the absence of any gelling agent from a pear juice as a green precursor. Our findings showed that the volatile nature of acetone, basic media, and cellulose content in pear juice played key roles in the formation of CDWG. This fabrication strategy of CDWG from a green precursor in absence of gelling agent could be more advantageous over CD-hybrids gel. Further, the fabricated gel exhibited excitation dependent red shifted multicolor (blue-green-yellow-orange) emission due to the presence of characteristic hydrophilic surface in CDs. The other unique feature of the work involved utilization of inherent fluorescent property of CDs in establishing optical interaction between 0D CDWG and 2D reduced graphene oxide (G) and graphene oxide (GO). It may be concluded that the quenching is mainly guided by the electron rich CDs and electron acceptance ability, large specific surface area of G and GO. It is also interesting to note that the introducing of gel property in CDs exhibit improved sensing efficiency and limit of detection of CDWG (1.5 μg ml À 1 ) for G. Further, such optical sensing could be beneficial for the fabrication of optoelectronics, photovoltaic devices and sensing of bio-molecules and metal ions.[a] J.

Biomolecule-derived quantum dots for sustainable optoelectronics

“…1,[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] Plant extracts have been demonstrated to be exceptional sources for the green fabrication of biodots, especially C-QDs and G-QDs, since they are rich carbon-containing species. 1,[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] Plant extract-derived QDs have shown tremendous physical features including high photoluminescence quantum yield (QY), photostability, excellent water solubility and lower cytotoxicity compared to ordinary dye and metal-based QDs, and thus demonstrated application potential in bioimaging, biosensing, photocatalysis and optoelectronics. 1,2,[31][32][33]…”

“…34 (v) Similarly, a C-QD-based weak gel from pear juice, with excitation dependent multicolour emissions, was also reported and used for sensing purposes. 35 Seeds have also used to synthesize biodots (including C-QDs and G-QDs). For example, (i) the microwave-assisted synthesis of self-assembled G-QDs (with a QY of 31.79% and excitationdependent luminescence) from grape seed extract was reported, which were used in nucleus targeting in theranostics, organelle labelling, and optical pH sensing probes.…”

“…The added advantages of scalability, biocompatibility and costeffectiveness of biomolecule-derived QDs in addition to their tunable and superior optical features make them alternative and smart choices compared to conventional semiconductor QDs for applications ranging from biodiagnostics to optoelectronics. Accordingly, different biomolecules such as plant extracts including fruits, seeds, peels, leaves, owers, roots and vegetables, [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] sugars including monosaccharides and polysaccharides, [51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69] different amino acids and proteins, [70][71][72][73][74][75][76]…”

Facile preparation of high fluorescent carbon quantum dots from orange waste peels for nonlinear optical applications

“…Among various nonlinear optical materials, ‘green' carbon source CDs have shown the maximum nonlinear optical properties. Recent articles have demonstrated CQD synthesis using many natural materials and with an option to re‐use natural waste . Orange waste peels are underused natural resources and it is still challenging to use these leftover residues effectively.…”

“…Recent articles have demonstrated CQD synthesis using many natural materials and with an option to re-use natural waste. [12][13][14][15][16][17][18][19][20][21] Orange waste peels are underused natural resources and it is still challenging to use these leftover residues effectively. For CQD synthesis, carbonization of glucose, sucrose, glycol, glycerin, and citric acid has received significant attention.…”