Bright Yellow Fluorescent Carbon Dots as a Multifunctional Sensing Platform for the Label-Free Detection of Fluoroquinolones and Histidine

Abstract

Owing to their diverse properties, fluorescent carbon dots (CDs) have attracted more attention and present enormous potential in development of sensors, bioimaging, drug delivery, microfluidics, photodynamic therapy, light emitting diode, and so forth. Herein, a multifunctional sensing platform based on bright yellow fluorescent CDs (Y-CDs) was designed for the label-free detection of fluoroquinolones (FQs) and histidine (His). The Y-CDs with superior optical and biological merits including high chemical stability, good biocompatibility, and low cytotoxicity were simply synthesized via one-step hydrothermal treatment of o-phenylenediamine (o-PD) and 4-aminobutyric acid (GABA). The Y-CDs can be utilized to directly monitor the amount of FQs based on fluorescence static quenching owing to the specific interaction between FQs and Y-CDs. Then, the fluorescence of this system can be effectively recovered upon addition of His. The multifunctional sensing platform exhibited high sensitivity and selectivity toward three kinds of FQs and His with low detection limits of 17–67 and 35 nM, respectively. Benefiting from these outstanding characters, the Y-CDs were successfully employed for trace detection of FQs in real samples such as antibiotic tablets and milk products. Furthermore, the probe was also extended to cellular imaging. All of the above prove that this multifunctional sensing platform presents great prospect in multiple applications such as biosensing, biomedicine, disease diagnosis, and environmental monitoring.

The Role of Amino Acids in Neurotransmission and Fluorescent Tools for Their Detection

“…However, this sensor appears to also respond to aspartate and tryptophan and its use has not been demonstrated in living cells. Another sensor, using bright yellow carbon dots functionalized with o -phenylenediamine and GABA, has also been reported to detect histidine specifically (Table 2) [ 302 ]; however, similar to the CuInS 2 -based sensor [ 301 ], this sensor requires the addition of a fluoroqinolone to first quench the fluorescence before recovery with histidine [ 302 ]. Testing of these carbon dots in human hepatoma cells showed good intracellular uptake with minimal cytotoxicity, suggesting that they may be used to image intracellular histidine dynamics in living cells.…”

Excitons in Carbonic Nanostructures

“…Nowadays, the emissive carbon dots covering the whole visible spectral range down to the near infrared have been reported [133,134]. They emit bright fluorescence with band maxima observed in yellow [135,136], orange [137,138], and red [78,139,140] colors. The near-IR absorbing and emitting nanoparticles were recently obtained [141,142].…”

Self‐Quenching‐Resistant Red Emissive Carbon Dots with High Stability for Warm White Light‐Emitting Diodes with a High Color Rendering Index

“…Carbon dots (CDs), an emerging class of carbon‐based luminescent nanomaterials, have attracted more and more attention and interest in recent years owing to their outstanding properties, such as chemical stability, [ 10,11 ] photostability, [ 12–14 ] biocompatibility, [ 15,16 ] and low toxicity. [ 17–19 ] Because of those distinct merits, CDs could be able to apply in extensive fields, such as drug delivery, [ 20,21 ] solar cell, [ 22 ] optoelectronic devices, [ 23,24 ] bioimaging, [ 25,26 ] and so on. Innumerable explorations in WLEDs filed are emerging repeatedly because of remarkable optical characteristic of CDs, such as strong UV absorption, tunable fluorescence emission, high thermal stability, and photostability.…”