Facile preparation of holmium(III)-doped carbon nanodots for fluorescence/magnetic resonance dual-modal bioimaging

Multilevel, Dual-Readout Logic Operations Based on pH-Responsive Holmium(III)-Doped Carbon Nanodots

“…Since Ho 3+ chelates and Ho 3+ complexes are well-documented T 2 contrast agents, − and the deconvoluted XPS Ho 4d spectra confirmed the +3 oxidation state of Ho in the Ho-CDs, it is reasonably anticipated that the Ho-CDs should exhibit T 2 enhanced contrast capability. However, as shown in Figure B, the Ho-CDs could enhance the brightness of gray-scaled T 1 -weighted MR images, and its r 1 relaxivity was calculated to be 2.049 mM –1 s –1 from the r 1 relaxivity curve.…”

“…Although there are the above various successful examples, it is still imperative to explore more signal combinations for the development of multireadout logic systems with better operation stability, especially for biomedical applications. Recently, inspired by their successful applications in clinical practice, the FL/magnetic resonance (MR) dual-modal imaging probes, which exhibit the collective merits of single-cell sensitivity and three-dimensional (3D) spatial resolution, have attracted intensive research attention. − Therefore, it is also of great significance to explore the feasibility of the FL/MR signal combination for designing multireadout logic systems, since the signal combination of FL/MR might render molecular logic devices better practicality in biomedical applications.…”

“…Due to its remarkable features such as facile synthesis, easy surface functionalization, as well as excellent water solubility and biocompatibility, carbon nanodots (CDs) have been successfully demonstrated as a versatile platform for developing bioimaging probes, nanoscale chemo/biosensors, molecular logic devices, drug delivery vehicles, etc . ,,− In particular, CDs are becoming a superior scaffold to construct multimodal probes for in vivo bioimaging. Magnetic elements such as Gd 3+ , or Mn 2+ , have been successfully doped into CDs to synthesize FL/MR dual-modal bioimaging nanoprobes.…”

“…Magnetic elements such as Gd 3+ , or Mn 2+ , have been successfully doped into CDs to synthesize FL/MR dual-modal bioimaging nanoprobes. Despite the fact that Ho 3+ has the shortest electronic relaxation time and the largest effective magnetic moment (μ eff = 10.6 μ B , significantly higher than Gd 3+ (μ eff = 8.0 μ B )) among lanthanide ions, − its potential of being doped into CDs to prepare FL/MR dual-modal bioimaging nanoprobes has been virtually unexplored. More importantly, taking advantages of the versatile surface chemistry of the Ho 3+ -doped CDs (Ho-CDs), it is possible to transform the molecular events in logic systems into both FL and MR changes, which in turn can be employed as measurable outputs.…”

Logic Gate Design Using Multicolor Fluorescent Carbon Nanodots for Smartphone-Based Information Extraction

“…An advantage of multicolor fluorophores was the simplification of handling procedures of multiple analyses, as well as their response to multiple analytes that enable the easy design of various logic gates. , Fascinatingly, carbon nanodots (CDs) have particular superiority in molecular logic gates especially due to their tunable photoluminescence. Extensive efforts have been made to investigate luminescent mechanisms and establish protocols to synthesize multicolor CDs for bioimaging, chemo-/biosensing, photocatalysis, photovoltaics, etc. − Different functional groups on the CD surface made them suitable candidates for implementing logic operations due to their rapid fluorescence “turn-on” or “turn-off” response to analytes . Actually, CDs with ultrafine dimensions have substantially contributed to developing recognition-based molecular logic gates using fluorescence as the readout signal in recent years. − The logic output can be observed by the change in intensity or wavelength of emission or absorption, establishing the basis of the logic operation via the known Boolean arithmetic function. , Obviously, multicolor CD-based logic gates show great potential for optical sensing, leading to a new detection strategy in the field of molecular diagnosis.…”