Green synthesis of fluorescent carbon dots from carrot juice for in vitro cellular imaging

Abstract

We report the use of carrot, a new and inexpensive biomaterial source, for preparing high quality carbon dots (CDs) instead of semi-conductive quantum dots for bioimaging application. The as-derived CDs possessing down and up-conversion photoluminescence features were obtained from carrot juice by commonly used hydrothermal treatment. The corresponding physiochemical and optical properties were investigated by electron microscopy, fluorescent spectrometry, and other spectroscopic methods. The surfaces of obtained CDs were highly covered with hydroxyl groups and nitrogen groups without further modification. The quantum yield of as-obtained CDs was as high as 5.16%. The cell viability of HaCaT cells against a purified CD aqueous solution was higher than 85% even at higher concentration (700 μg mL −1 ) after 24 h incubation. Finally, CD cultured cells exhibited distinguished blue, green, and red colors, respectively, during in vitro imaging when excited by three wavelength lasers under a confocal microscope. Offering excellent optical properties, biocompatibility, low cytotoxicity, and good cellular imaging capability, the carrot juice derived CDs are a promising candidate for biomedical applications.

Label‐Free Fluorometric Detection of Adulterant Malachite Green Using Carbon Dots Derived from the Medicinal Plant Source Ocimum tenuiflorum

“…It showed characteristic excitation‐dependent fluorescence with maximum intensity for 320 nm excitation wavelength ( Figure b). Carbon quantum dots reflected strong blue fluorescence near 405 nm with a Stokes’ shift of 90 nm as seen with other reports …”

“…Among these, hydrothermal method has been extensively used as a cheaper eco‐friendly alternative which often uses natural sources as precursors eliminating the need of surface passivation of the carbon dots. A huge variety of natural sources have been used like apple, cashew and many others . This synthetic route has garnered great interest because of the simplicity of the synthesis approach eliminating the need of using costly and sophisticated procedures, additional and often toxic chemical reagents, solvents and acids.…”

Bioimaging Applications of Carbon Nanodots: A Review

“…In contrast, breaking down macroscopic materials (such as food products and plants) to produce CNDs, is the principle of top-down approach [3,13]. Many different materials have been used to develop CNDs, including apple seeds [14], Citrus sinensis or Citrus limon peels [15], human fingernails [16,17], cotton [18], citrulline [19], coriander leaves [20], carrot juice [21], citric acid and tris(hydroxymethyl) methylaminomethane [22], polyethyleneimine, nitric acid [23], and many others. Additionally, many different procedures can be employed to produce CNDs, with the most commonly employed method being the solvothermal carbonization, pyrolysis, and microwave treatment [7,[24][25][26][27].…”

Molecular imaging with nanoparticles: the dwarf actors revisited 10 years later

“…To give a taste of the luxurious proliferation of potential raw materials used to create carbon dots we append here an incomplete list, it includes: soot (Allam and Sarkar 2011; Liu et al 2007; Vinci and Colón 2012; Baker and Colón 2009), carbon nanotubes (Bottini et al 2006; Zhou et al 2007), carbon fibers (Vinci et al 2015), graphene sheets (Pan et al 2010), activated carbon (Qiao et al 2010; Li et al 2011b; Dong et al 2010), graphite (Sun et al 2006; Hu et al 2009; Cao et al 2007; Zhao et al 2008; Lu et al 2009; Zheng et al 2009, 2011; Wang et al 2011) various small organic molecules (Zheng et al 2015) such as acetic acid (Fang et al 2011), amino acids (Wei et al 2014), citric acid or glucose (Dong et al 2012a, b), sucrose (Zhang et al 2010), carbohydrates (Liu et al 2011a, b; Peng and Travas-Sejdic 2009), C 60 molecules (Lu et al 2011), and nanodiamonds (Yu et al 2005a, b; Chang et al 2008; Wolfbeis 2015). Research on these eco-friendly nanoparticles blossomed from 2014 onwards, extending the syntheses to a further wide range of natural raw-stuffs and ecologically friendly syntheses including: wool (Wang et al 2016a), flour (Zhang et al 2015), bagasse (Du et al 2014), radishes (Liu et al 2017a), orange juice (Sahu et al 2012), peaches (Atchudan et al 2016), coffee grounds (Hsu et al 2012), garlic (Sun et al 2016), coriander (Sachdev and Gopinath 2015), papaya (Wang et al 2016a, b, c, d), carrots (Liu et al 2017b), potatoes (Shen et al 2017), waste frying oil (Hu et al 2014), waste biomass (Suryawanshi et al 2014) and pigeon feathers, eggs and manure (Ye et al 2017); the list becomes longer almost every day. The number of protocols reported for preparation of carbon dots is almost equally long, see below.…”