Carbon Dots Prepared by Hydrothermal Treatment of Dopamine as an Effective Fluorescent Sensing Platform for the Label‐Free Detection of Iron(III) Ions and Dopamine

Abstract

A facile, economic and green one-step hydrothermal synthesis route using dopamine as source towards photoluminescent carbon nanoparticles (CNPs) is proposed. The as-prepared CNPs have an average size about 3.8 nm. The emission spectra of the CNPs are broad, ranging from approximately 380 (purple) to approximately 525 nm (green), depending on the excitation wavelengths. Due to the favorable optical properties, the CNPs can readily enter into A549 cells and has been used for multicolor biolabeling and bioimaging. Most importantly, the as-prepared CNPs contain distinctive catechol groups on their surfaces. Due to the special response of catechol groups to Fe(3+) ions, we further demonstrate that such wholly new CNPs can serve as a very effective fluorescent sensing platform for label-free sensitive and selective detection of Fe(3+) ions and dopamine with a detection limit as low as 0.32 μM and 68 nM, respectively. The new "mix-and-detect" strategy is simple, green, and exhibits high sensitivity and selectivity. The present method was also applied to the determination of Fe(3+) ions in real water samples and dopamine in human urine and serum samples successfully.

From highly graphitic to amorphous carbon dots: A critical review

“…6(d) ] reveals characteristic absorption peaks due to the octadecyl chains tethered to the surface along with a strong peak at 1700 cm −1 suggestive of amide linkages. 49 Similarly, water dispersible C-dots were prepared by controlled pyrolysis of dopamine, 54 lauryl gallate, 55 polyethylenimine, 56 or a mixture of ethanolamine and citric acid. 57 , 58 In a remarkably time-effi cient modifi cation of the method, microwave-assisted thermal treatment of an aqueous solution containing PEG 48 or a mixture of PEG and a saccharide 59 leads rapidly to selfpassivated colloidal aC-dots.…”

“…62 Chemical groups generated in situ during the synthesis of C-dots can impart additional functionalities. For example, the gC-dots derived by hydrothermal treatment of dopamine 54 bear distinctive catechol groups on their surface, offering a sensing platform for the detection of Fe(III) ions and dopamine. In another approach, the thermal treatment of a mixture of citric acid and ethanolamine results in the evolution of a series of photoactive materials.…”

One-Step Microwave-Assisted Green Synthesis of Luminescent N-Doped Carbon Dots from Sesame Seeds for Selective Sensing of Fe(III)

“…The nitrogen-doped carbon dots must be having some co-ordination interaction with Fe(III) because of the occurrence of electron-rich nitrogen atom in the structure. This could result in nonradiative electron transfer between them which can cause a substantial quenching of photoluminescence of carbon dots 41,42 . This electron transfer process plays a major role for the significant quenching of C.dots fluorescence.…”

One-step fabrication of high quantum yield sulfur- and nitrogen-doped carbon dots for sensitive and selective detection of Cr(vi)

“…), [12][13][14][15][16][17] and some organic compounds (such as glucose, DNA, vitamin B12, and dopamine, etc.). [18][19][20][21] Recently, graphene quantum dot membrane, 22 boron and nitrogen co-doped carbon dots, 23 cobalt(II)-doped carbon dots, 24 and phosphate functionalized carbon dots 25 have all been successfully employed as probes for the determination of Cr(VI). But as far as we know, the uorescent probes for Cr(VI) in previous reports have involved organic reagent, complex process and severe synthetic conditions.…”