Where is the best substitution position for amino groups on carbon dots: a computational strategy toward long-wavelength red emission

Abstract

Carbon dots (CDs) are a promising fluorescent material in biological and optoelectronic applications owing to their high biocompatibility, low cytotoxicity, and high stability. Red emission CDs are not only widely...

Revealing the synergetic interaction between amino and carbonyl functional groups and their effect on the electronic and optical properties of carbon dots

“…These absorption peaks at 256 nm and 441 nm might correspond to the pp* transition of sp 2 CQC bonds and np* transition of the C-N, CQO, or CQN bonds, typically the CDs absorption peak, respectively. 24,40 Concerning the pristine CDs, the carbonyl CDs exhibited a new absorption peak at the longer wavelength extended to the first Near Infra-Red (NIR) window region. In varying the O/C atomic ratios, the carbonyl CDs show the longest absorbance peaks at 640, 719, and 760 nm for the O/C atomic ratios of 0.04, 0.07, and 0.11, respectively (Fig.…”

“…Thus, a charge transfer is more responsible for tuning the CDs' optical and electronic properties. 1,14,19 The amino and carbonyl groups were simultaneously functionalized in bottom-up preparation on the CDs' surface. 19,24,49 Then, it is highly intriguing to utilize their presence to tune the CDs' optical and electronic properties.…”

“…In recent years several comprehensive studies to further the understanding of the role of surface functional groups in the electronic and optical properties of CDs have been conducted based on computational and experimental studies. 9,11–15 This knowledge significantly broadens the potential application of CDs in various applications, such as energy conversion, catalysis, and biomedicine. 16–20 For example, as is well known, the absorption peaks of CDs are mainly in the UV and visible light regions.…”

Regulation of multi-color fluorescence of carbonized polymer dots by multiple contributions of effective conjugate size, surface state, and molecular fluorescence

“…To this end, it is of great importance to develop new strategies that can easily modulate the emission colors of CDs, which can further advance their practical applications in diverse fields. 27…”

“…To this end, it is of great importance to develop new strategies that can easily modulate the emission colors of CDs, which can further advance their practical applications in diverse fields. 27 CDs are currently classified into four main categories, including graphene quantum dots (GQDs), carbon quantum dots (CQDs), carbon nanodots (CNDs), and carbonized polymer dots (CPDs). 28 Generally speaking, any CDs formed by the polymerization of small molecules can be called CPDs.…”