Simple Approach to Synthesize Amino-Functionalized Carbon Dots by Carbonization of Chitosan.

Xin Liu,Xueming Zhang,Feng Xu,Jinhui Pang

doi:10.1038/srep31100

Abstract

Carbon dots (CDs) as a new series of fluorescent nanomaterials have drawn great attention in recent years owning to their unique properties. In this paper, a simple carbonization approach to synthesize amino-functionalized CDs was developed by using chitosan as the carbon precursor. The as-prepared CDs possessed desirable amino function group on their surface and exhibited bright luminescence with absolute quantum yield (QY) of 4.34%, excitation-, pH-dependent and up-conversion fluorescence behaviors. Furthermore, we have investigated the cytotoxicity and biocompatibility of the as-prepared CDs, which demonstrated that the as-prepared CDs have the potential applications in biosensing, cellular imaging and drug delivery.

Highlights

Carbon dots (CDs) as a new member of carbon nanomaterials have drawn a great deal of attention, owning to their chemical stability, excellent water solubility, tuneable fluorescence properties, low cost, low toxicity, good biocompatibility and environmental friendliness[1,2,3,4]
Chitosan is the N-deacetylated derivative of chitin, containing high amount of amino (-NH2) and hydroxyl (-OH) functional groups, accepted as carbon source to synthesize CDs owing to its natural, nontoxic and biocompatible properties[20,21]
We presented a very simple approach to synthesize amino-functionalized CDs by one-step carbonization treatment of chitosan (Fig. 1), which was scarcely studied before

Summary

Introduction

Carbon dots (CDs) as a new member of carbon nanomaterials have drawn a great deal of attention, owning to their chemical stability, excellent water solubility, tuneable fluorescence properties, low cost, low toxicity, good biocompatibility and environmental friendliness[1,2,3,4]. “bottom-up” approach consists of microwave/ultrasonic preparation, plasma treatment, hydrothermal/acidic oxidation route and carbonizing organics route[12,13,14] Many of these synthesis methods involve expensive or toxic starting materials, high temperature, long reaction time and further surface-passivation[15,16]. We presented a very simple approach to synthesize amino-functionalized CDs by one-step carbonization treatment of chitosan (Fig. 1), which was scarcely studied before In this method, neither a strong acid solvent nor surface passivation reagent was used. Due to their low toxicity and fine aqueous dispersibility, the as-prepared CDs showed great potential in biosensing, cellular imaging and drug delivery applications

Methods

Results

Conclusion