Semiconducting Polymer Dot-Based Ratiometric Fluorescence Nanoprobe for DNA Detection

A ratiometric fluorescent deoxyribonucleic acid probe was synthesized using the photoinduced electron transfer mechanism, involving the interactions between different fluorescent components and electron acceptors. Double-emission carboxyl functionalized semiconducting polymer dots were synthesized using the nanoprecipitation method and applied as the flurophore, while methylene blue was used as the electron acceptor. Photoinduced electron transfer between different polymer dots components and methylene blue can achieve ratiometric modulation of the overall fluorescence in the system. The addition of deoxyribonucleic acid restores the fluorescence intensity, because the stronger interactions between deoxyribonucleic acid and methylene blue results in methylene blue being separated from the polymer dots. Under the optimized experimental conditions, system fluorescence was restored to its maximum when the concentration of deoxyribonucleic acid reached 200 nM, the linear range was 0.006-200 nM (R2 = 0.995). This probe was reasonably free from interference, showing a good response to deoxyribonucleic acid, with strong application data from actual samples.

A fluorescence nanoprobe for detecting the effect of different oxygen and nutrient conditions on breast cancer cells migration and invasion

Cancer cell migration and invasion are initial steps for tumor metastasis that increases patient mortality. Tumor microenvironment is characterized by hypoxic and low nutrient-containing. Previous studies have suggested that hypoxia...

Eu3+ Functionalized CQDs Hybrid Material: Synthesis, Luminescent Properties and Sensing Application for the Detection of Cu2+

In this work, we develop a novel flexible method to construct a lanthanide dual-emitting ratiometric fluorescence nanoprobe with excellent luminescence properties and significantly selectivity for the detection of copper ions,...

Bacterium-Derived Carbon Dots as a Novel “Turn-On-On-Off-On” Sensor for Cr(VI) and 4-Nitrophenol Detection Based on Inner Filter Effect Mechanism

Phenolic compounds, especially 4-nitrophenol (4-NP), and chromium (VI) are highly toxic environmental pollutants. Thus, it is significantly important to establish a rapid and sensitive sensor for 4-NP and Cr(VI) monitoring in environment. In this paper, a novel approach has been adopted where E. coli-derived CDs (CDs-WT) prepared by one step hydrothermal method previously and sensitized by ampicillin (turn-on) were used as fluorescence nanoprobe (CDs-WT-Amp) for 4-NP and Cr(VI) determination based on the inner filter effect quenching mechanism (turn-off). Then, the quenching fluorescence was reversed by addition of ampicillin (turn-on). The linear ranges of 4-NP and Cr(VI) detection were 0–50[Formula: see text][Formula: see text]M and 0–25[Formula: see text][Formula: see text]M, with the limits of detection 88.89[Formula: see text]nM and 64.75[Formula: see text]nM, respectively. The “turn-on-on-off-on” fluorescent nanosensor system was successfully used to determine Cr(VI) and 4-NP in water with satisfactory results. It shows that the “turn-on-off-on” nanoprobe has great promising potential for application to environmental pollutant detection.