Mono-phase ceramics of monticellite (CaMgSiO4) were successfully synthesized by sintering sol-gel-derived monticellite powder compacts at 1,480 degrees C for 6 h. The mechanical properties and the coefficient of thermal expansion (CTE) of the monticellite ceramics were tested. In addition, the bioactivity in vitro of the monticellite ceramics was evaluated by investigating their bone-like apatite-formation ability in simulated body fluid (SBF), and the biocompatibility in vitro was detected by osteoblast adhesion and proliferation assay. The results showed that the bending strength, fracture toughness and Young's modulus of the monticellite ceramics were about 159.7 MPa, 1.63 MPa m1/2 and 51 GPa, respectively. The CTE was 10.76x10(-6) degrees C(-1) and close to that of Ti-6Al-4V alloy (10.03x10(-6) degrees C(-1)). Furthermore, the monticellite ceramics possessed bone-like apatite-formation ability in SBF and could release soluble ionic products to significantly stimulate cell growth and proliferation. In addition, osteoblasts adhered and spread well on the monticellite ceramics, which indicated good bioactivity and biocompatibility.

Poly(ethylene glycol) passivated graphene quantum dots (PEG-GQDs) were synthesized based on a green and effective strategy of the hydrothermal treatment of cane molasses. The prepared PEG-GQDs, with an average size of 2.5 nm, exhibit a brighter blue fluorescence and a higher quantum yield (QY) (up to approximately 21.32%) than the QY of GQDs without surface passivation (QY = 10.44%). The PEG-GQDs can be used to detect and quantify paramagnetic transition-metal ions including Fe 3+ , Cu 2+ , Co 2+ , Ni 2+ , Pb 2+ , and Mn 2+ . In the case of ethylenediaminetetraacetic acid (EDTA) solution as a masking agent, Fe 3+ ions can be well selectively determined in a transition-metal ion mixture, following the lowest limit of detection (LOD) of 5.77 μM. The quenching mechanism of Fe 3+ on PEG-GQDs belongs to dynamic quenching. Furthermore, Fe 3+ in human serum can be successfully detected by the PEG-GQDs, indicating that the green prepared PEG-GQDs can be applied as a promising candidate for the selective detection of Fe 3+ in clinics.

The aim of this research was to investigate the effect of the chemical composition on the mechanical properties, bioactivity, and cytocompatibility in vitro of bioceramics in the MgO-CaO-SiO(2) system. Three single-phase ceramics (merwinite, akermanite and monticellite ceramics) with different MgO contents were fabricated. The mechanical properties were tested by an electronic universal machine, while the bioactivity in vitro of the ceramics was detected by investigating the bone-like apatite-formation ability in simulated body fluid (SBF), and the cytocompatibility was evaluated through osteoblast proliferation and adhesion assay. The results showed that their mechanical properties were improved from merwinite to akermanite and monticellite ceramics with the increase of MgO contents, whereas the apatite-formation ability in SBF and cell proliferation decreased. Furthermore, osteoblasts could adhere, spread and proliferate on these ceramic wafers. Finally, the elongated appearance and minor filopodia of cells on merwinite ceramic were more obvious than the other two ceramics.

Carbon dots have attracted much attention due to their high fluorescence intensity, easy modification, good stability, and biocompatibility. However, the realization of low‐cost mass production of high‐quality carbon dots still faces great challenges. Biomass is of non‐toxic and environmentally friendly organism, but a lot of biomass is treated as waste for burning and landfill at present, causing irreparable pollution to the environment. In fact, many biomass resources are ideal candidates for preparing carbon dots. This review focuses on carbon dots including carbon quantum dots (CQDs) and graphene quantum dots (GQDs) which using biomass as carbon source on the aspects of plants and their derivatives, animals and their derivatives and municipal waste. The characterization of the structure and composition of biomass carbon dots, the regulation of fluorescence color and the methods of improving quantum yield (QY) including heteroatom doping and surface modification are introduced in detail. Moreover, biomass carbon dots for detecting metal ions and non‐metal molecules and their quenching mechanism are emphatically introduced in addition to summarizing the luminescence mechanism, and some promising prospects and challenges in this uplifting field are discussed.

The ceramic of merwinite (Ca3MgSi2O8) was prepared by sintering sol-gel-derived merwinite powder compacts. The mechanical properties and the coefficient of thermal expansion (CTE) of the merwinite ceramic were determined. In vitro bioactivity of the merwinite ceramics was evaluated. Our results showed that the sintered body was single-phase merwinite ceramic, and that its bending strength, fracture toughness and Young's modulus were approximately 151 MPa, 1.72 MPa m(1/2) and 31 GPa, respectively. The CTE of the ceramic was 9.87 x 10(-6) degrees C(-1) and close to that for the Ti-6Al-4V alloy (9.80 x 10(-6) degrees C(-1)). Immersion of the sintered body in simulated body fluid induced surface precipitation of Ca-P rich layers. Cell culture experiment results confirmed that soluble ionic products from merwinite dissolution significantly stimulated osteoblast proliferation, and osteoblasts adhered and spread well on merwinite ceramic surfaces.