Nanosized carbon dots (CDs) are emerging as superior fluorophores for biosensing and a bioimaging agent with excellent photostability, chemical inertness, and marginal cytotoxicity. This paper reports a facile one-pot strategy to immobilize the biocompatible and fluorescent CDs (∼6 nm) into the glucose-imprinted poly(N-isopropylacrylamide-acrylamide-vinylphenylboronic acid) [poly(NIPAM-AAm-VPBA)] copolymer microgels for continuous optical glucose detection. The CDs designed with surface hydroxyl/carboxyl groups can form complexes with the AAm comonomers via hydrogen bonds and, thus, can be easily immobilized into the gel network during the polymerization reaction. The resultant glucose-imprinted hybrid microgels can reversibly swell and shrink in response to the variation of surrounding glucose concentration and correspondingly quench and recover the fluorescence signals of the embedded CDs, converting biochemical signals to optical signals. The highly imprinted hybrid microgels demonstrate much higher sensitivity and selectivity for glucose detection than the nonimprinted hybrid microgels over a clinically relevant range of 0-30 mM at physiological pH and benefited from the synergistic effects of the glucose molecular contour and the geometrical constraint of the binding sites dictated by the glucose imprinting process. The highly stable immobilization of CDs in the gel networks provides the hybrid microgels with excellent optical signal reproducibility after five repeated cycles of addition and dialysis removal of glucose in the bathing medium. In addition, the hybrid microgels show no effect on the cell viability in the tested concentration range of 25-100 μg/mL. The glucose-imprinted poly(NIPAM-AAm-VPBA)-CDs hybrid microgels demonstrate a great promise for a new glucose sensor that can continuously monitor glucose level change.

Cost-efficient nanoparticle carbocatalysts composed of fluorescent carbon dots (CDs) embedded in carbon matrix were synthesized via one-step acid-assisted hydrothermal treatment (200 °C) of glucose. These as-synthesized CD-based carbocatalysts have excellent photoluminescence (PL) properties over a broad range of wavelengths and the external visible or NIR irradiation on the carbocatalysts could produce electrons to form electron-hole (e(-)-h(+)) pairs on the surface of carbocatalysts. These restant electron-hole pairs will react with the adsorbed oxidants/reducers on the surface of the CD-based carbocatalysts to produce active radicals for reduction of 4-nitrophenol and degradation of dye molecules. Moreover, the local temperature increase over CD-based carbocatalyst under NIR irradiation can enhance the electron transfer rate between the organic molecules and CD-based carbocatalysts, thus obviously increase the catalytic activity of the CD-based carbocatalyst for the reduction of 4-nitrophenol and the degradation of dye molecules. Such a type of CD-based carbocatalysts with excellent properties and highly efficient metal-free photocatalytic activities is an ideal candidate as photocatalysts for the reduction of organic pollutants under visible light and NIR radiation.

Fly ash can be used as a filler in polymer composite materials. Two fly ash samples (one from the UK, UKFA, and another one from South Africa, SAFA) were washed with water and HCl and compared to investigate their interaction with a commercial coupling agent employed to enhance their incorporation into the polymer matrix. The removal of certain ions from the filler surface resulted in a decrease in the heat of adsorption values due to the reduced number of linkage points for the coupling agent. The coupling agent-filler interaction was possible for some of the metals of the second group (calcium, magnesium, and sodium) and some of the "p" group (aluminum, sulfur, and phosphorous) on the surface of fly ash.