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A sensitive polymer dots fluorescent sensor for determination of α-L-fucosidase activity in human serum
摘要： α-L-Fucosidase (AFu) is an important biomarker for early diagnosis of hepatocellular carcinoma and fucosidosis. In this study, a novel, sensitive and selective polymer dots (PDs) fluorescent sensing strategy based on inner filter effect was firstly developed for AFu activity determination. The PDs with a high quantum yield of 53.6% were synthesized by a mild one-pot method. The detection mechanism of this strategy was based on inner filter effect between PDs and p-nitrophenol (PNP) which was the hydrolyzate of 4-nitrophenyl-α-L-fucopyranoside (PNPF) catalyzed by AFu. The absorption of PNP overlapped the fluorescence excitation spectrum of the PDs, which resulted in a fluorescence quenching or weakening of PDs. The sensing system showed a good linear relationship within 0.01-0.9 U L-1 and provided a low AFu detection limit of 0.001 U L-1 (S/N=3). This PDs sensor were successfully applied for the determination of AFu in human serum samples.
关键词： Human serum,α-L-Fucosidase,Polymer dots,Inner filter effect,Fluorescent sensor
更新于2025-11-19 16:46:39
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Polymer Dots Compartmentalized in Liposomes as Photocatalyst for In Situ Hydrogen Therapy
摘要： Semiconducting polymer dots (Pdots) have recently attracted considerable attention because of their photocatalytic activity as well as tunable optical band gap. In this contribution, we describe the therapeutic application of Pdots through in situ photocatalytic hydrogen generation. A liposome was employed as a nanoreactor to confine the Pdot photocatalyst, reactants, intermediates, and by-products. Upon photon absorption by the Pdots, the catalytic cycle is initiated and repeated within the aqueous interior, while the H2 product diffuses across the lipid bilayer to counteract reactive oxygen species (ROS) overexpressed in diseased tissues. Ensemble and single-particle F?rster resonance energy transfer microscopy confirmed the proposed nanoreactor model. We demonstrate that a liposomal nanoreactor containing Pdots and a sacrificial electron donor is a potential photocatalytic nanoreactor for in situ hydrogen therapy.
关键词： compartmentalization,hydrogen therapy,photocatalysis,polymer dots,liposomes
更新于2025-09-23 15:22:29
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Preparation and comparison of molecularly imprinted polymer fluorimetric nanoprobe based on polymer dots and carbon quantum dots for determination of acetamiprid using response surface method
摘要： In this study molecularly imprinted polymers (MIP) based on carbon quantum dots (CQDs) and polymer dots (PDs) are developed for selective determination of acetamiprid using fluorometry. The measurement is based on the fluorescence quenching of CQDs and PDs in the presence of acetamiprid. PDs were prepared using a one-step aqueous synthesis method from ascorbic acid and diethylenetriamine at room temperature. CQDs were prepared from the same materials using the hydrothermal method at 180 °C. These particles were characterized using field emission scanning electron microscopy (FE-SEM), FTIR, dynamic light scattering (DLS), X-ray diffraction (XRD), UV–Vis, and fluorescence. The quantum yield was 47% for PDs and 8% for CQDs. Then, molecularly imprinted polymers (MIP) were prepared based on PDs and CQDs using reverse microemulsion method. The fluorescence quenching of CQD@MIPs and PD@MIPs was investigated at an excitation wavelength of 350 nm and emission wavelength of 440 nm in the presence of a template. Other variables affecting the fluorescence peaking were optimized using design expert software. The results illustrate that the use of PD@MIPs had a wide dynamic range 0.08–109 nmol L?1, good accuracy and detection limit of 0.02 nmol L?1, while using CQD@MIPs led to a lower dynamic range 0.36–64 nmol L?1, and detection limit of only 0.11 nmol L?1. The responses of the optical nanoprobe for acetamiprid in water (recovery 92–102%) and apple (recovery 92–103%) were also investigated.
关键词： Molecularly imprinted polymers,Fluorescence quencing,Carbon dots,Polymer dots,Optical nanoprobe,Acetamiprid
更新于2025-09-23 15:21:01
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Semiconducting Polymer Dots as Broadband Saturable Absorbers for Q-switched Fiber Lasers
摘要： Semiconducting polymer dots (Pdots) have attracted much attention due to their outstanding optical properties. However, Pdots potential in laser technology is rare. Here, we first report the benzobisthiadiazole (BBT)-based Pdot as a single broadband nonlinear saturable absorber (SA) for passively Q-switched fiber lasers at 1, 1.5, and 2 μm. The Pdots-SA possesses a strong saturable absorption, broadband nonlinear optical response, and large modulation depth. Once the Pdots-SA is integrated into the ytterbium-, erbium-, and thulium-doped fiber laser cavities, stable Q-switched operations are observed at the central wavelengths of 1036, 1561, and 1951 nm. Our results verify that the Pdots are promising nonlinear media for Q-switched pulses generation, and highlight the potential of Pdots for relevant nonlinear optical applications.
关键词： Saturable absorber,Semiconducting polymer dots,Q-switched fiber lasers,Broadband nonlinear optical response
更新于2025-09-23 15:19:57
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Ratiometric Fluorescent Detection of Intracellular Singlet Oxygen by Semiconducting Polymer Dots
摘要： Singlet oxygen (1O2) plays important roles in many biological processes. However, it is very difficult to detect 1O2 in the intracellular environment owing to its relatively low concentration and short lifetime. Here, we developed a ratiometric probe based on semiconducting polymer dots (Pdots) that can sensitively detect 1O2 in live cells. An organic dye, singlet oxygen sensor green (SOSG), was doped in polyfluorene Pdots, and excitation energy was efficiently transferred from the polymer to the SOSG dye. Accordingly, the Pdots showed constant blue fluorescence as a reference, and increased green fluorescence upon singlet oxygen generation. The ratiometric response of Pdots was examined in the intracellular environment by in-situ 1O2 generation with a photosensitizer and light irradiation. Both spectroscopic measurements and confocal imaging were performed to monitor intracellular 1O2 generation during photodynamic therapy using the Pdot probe. Our results indicate that the SOSG-doped Pdots are promising for intracellular 1O2 detection.
关键词： Semiconducting polymer dots,Intracellular detection,Singlet oxygen,Photodynamic therapy,Ratiometric probe
更新于2025-09-11 14:15:04