2H-WS2Quantum Dots Produced by Modulating the Dimension and Phase of 1T-Nanosheets for Antibody-Free Optical Sensing of Neurotransmitters.
Modulating the dimensions and phases of transition metal dichalcogenides is of great interest to enhance their intrinsic properties or to create new physicochemical properties. Herein, we report an effective approach to synthesize 2H-WS2quantum dots (QDs) via the dimension and phase engineering of 1T-WS2nanosheets. The solvothermal reaction of chemically exfoliated 1T-WS2nanosheets in N-methyl-2-pyrrolidone (NMP) under an N2atmosphere induced their chopping and phase transition at lower temperature to produce 2H-WS2QDs with a high quantum yield (5.5 ± 0.3%). Interestingly, this chopping and phase transition process showed strong dependency on solvent; WS2QDs were not produced in other solvents such as 1,4-dioxane and dimethyl sulfoxide. Mechanistic investigations suggested that NMP radicals played a crucial role in the effective production of 2H-WS2QDs from 1T-WS2nanosheets. WS2QDs were successfully applied for the selective, sensitive, and rapid detection of dopamine in human serum (4 min, as low as 23.8 nM). The intense fluorescence of WS2QDs was selectively quenched upon the addition of dopamine and Au3+ions due to fluorescence resonance energy transfer between WS2QDs and the quickly formed Au nanoparticles. This new sensing principle enabled us to discriminate dopamine from dopamine-derivative neurotransmitters including epinephrine and norepinephrine, as well as other interference compounds.
Department of Chemical Engineering, Hanyang University , Ansan 426-791, Republic of Korea.
Man-Jin
MJ
Kim
Department of Chemical Engineering, Hanyang University , Ansan 426-791, Republic of Korea.
Su-Ji
SJ
Jeon
Department of Chemical Engineering, Hanyang University , Ansan 426-791, Republic of Korea.
Tae Woog
TW
Kang
Department of Chemical Engineering, Hanyang University , Ansan 426-791, Republic of Korea.
Jong-Min
JM
Ju
Department of Chemical Engineering, Hanyang University , Ansan 426-791, Republic of Korea.
DaBin
D
Yim
Department of Chemical Engineering, Hanyang University , Ansan 426-791, Republic of Korea.
Hye-In
HI
Kim
Department of Chemical Engineering, Hanyang University , Ansan 426-791, Republic of Korea.
Jung Hyun
JH
Park
Department of Chemical Engineering, Hanyang University , Ansan 426-791, Republic of Korea.
Jong-Ho
http://orcid.org/0000-0001-6256-7713
JH
Kim
D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D018377:Neurotransmitter Agents; D045663:Quantum Dots
D018377:Neurotransmitter Agents
WS2 quantum dots; dopamine detection; optical biosensors; optical modulation; phase engineering