Green preparation of fluorescent carbon dots from lychee seeds and their application for the selective detection of methylene blue and imaging in living cells

Abstract

A green approach was developed for the preparation of fluorescent carbon dots (CDs) by using lychee seed as precursor. The preparation of CDs was performed by simply pyrolysis. The quantum yield of asprepared CDs was 10.6% by using quinine sulfate as the reference. The CDs were employed as a fluorescence probe for the detection of methylene blue (MB). This sensing system exhibits excellent 10 sensitivity and selectivity toward MB, and a detection limit of 50 mM is achieved. The possible application of as-prepared CDs for imaging in living cells was also explored. The inherent cytotoxicity of CDs was evaluated using HepG2 cell, and the cell viabilities were estimated to be greater than 90% upon addition of the CDs over a wide concentration range of 0−1000 µg/mL. It was then successfully applied for the fluorescence imaging of HepG2 cells. 15 2 Experimental Materials and reagentsFresh lychee was purchased from a local market. After its skin 75

Biomass‐Derived Carbon Dots and Their Applications

“…In addition to plants, waste can also be used as a carbon source to prepare BCDs by pyrolysis, such as litchi seeds, litchi exocarp, coffee grounds, waste frying oil, watermelon peel, peanut shell, peanut skin, and the like. Water‐soluble fluorescent BCDs were prepared by simple pyrolysis using litchi seeds as a carbon source (Figure c). The prepared BCDs have a particle size of 0.4 to 2.0 nm, an average particle diameter of 1.12 nm, and a QY of 10.6%.…”

“…The prepared BCDs have potential applications in both biosensors and bioimaging. At the same time, lychee seeds and jujube kernel were also used to prepare BCDs for bioimaging. Then, foods that are commonly eat are also be used, cabbage, winter melon, garlic, allium fistulosum, etc .…”

“…In recent years, various biomass has been used as carbon sources to prepare BCDs ( Figure ). The biomass used includes walnut peel, garlic, papaya juice, rice husk, winter melon, lychee seeds, goose feather, silkworm chrysalis, bee pollen, milk, Phyllanthus acidus, and baked lamb . BCDs prepared using biomass have been applied to biological imaging, sensors, drug delivery, and other applications ( Scheme ).…”

A facile synthesis of nontoxic luminescent carbon dots for detection of chromium and iron in real water sample and bio‐imaging

“…The application of CDs as sensing probes is not limited to metal ion assaying. A significant amount of research has been done on detecting molecules, including methylene blue, glucose, etc., using CDs from bio‐resources.…”

Preparation of fluorescent organic nanoparticles from polyethylenimine and sucrose for cell imaging

“…And some green synthetic approaches for the preparation of CDs have also been developed by using inexpensive renewable resources as precursors like honey [12], ginger [13], lychee seeds [14], and peanut shells [15]. However, most of these approaches suffer from either high reaction temperatures or long preparation times.…”