@article {Dhenadhayalan20161252,
	title = {Unravelling the Multiple Emissive States in Citric-Acid-Derived Carbon Dots},
	journal = {Journal of Physical Chemistry C},
	volume = {120},
	number = {2},
	year = {2016},
	note = {<p>cited By 78</p>
},
	pages = {1252-1261},
	abstract = {<p>Steady-state and time-resolved fluorescence spectroscopy techniques were used to probe multifluorescence resulting from citric-acid-derived carbon dots (C-dots). Commonly, both carboxyl-/amine-functionalized C-dots exhibit three distinct emissive states corresponding to the carbon-core and surface domain. The shorter-wavelength fluorescence (below 400 nm) originates from the carbon-core absorption band at \~{}290 nm, whereas the fluorescence (above 400 nm) is caused by two surface states at \~{}350 and 385 nm. In addition to three emissive states, a molecular state was also found in amine-functionalized C-dots. Time-resolved emission spectra (TRES) and time-resolved area normalized emission spectra (TRANES) were analyzed to confirm the origin of excitation wavelength-dependent fluorescence of C-dots. The surface functional groups on the C-dots are capable of regulating the electron transfer to affect the multifluorescence behavior. The electron transfer takes place from the carbon-core to surface domain by the presence of -COOH on the surface and vice versa for the case of -NH2 present on the surface. To the best of our knowledge, this is the first report that the multiemissive states are probed in C-dots systems using TRES and TRANES analyses, and related fluorescence mechanisms are verified clearly. {\textcopyright} 2015 American Chemical Society.</p>
},
	keywords = {Citric acid, Electron transfer, Electron transitions, Emission spectroscopy, Emission spectrums, Excitation wavelength, Fluorescence, Fluorescence spectroscopy, Shorter wavelength, Surface domains, Surface functional groups, Time-resolved emission spectra, Time-resolved fluorescence spectroscopy},
	doi = {10.1021/acs.jpcc.5b08516},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84955516013\&doi=10.1021\%2facs.jpcc.5b08516\&partnerID=40\&md5=0421e5d1020ec6d0e669d6cb6760a6f6},
	author = {Dhenadhayalan, N. and Lin, K.-C. and Suresh, R. and Ramamurthy, P.}
}
