The treatment of infective or potentially infectious bone defects is a critical problem in the orthopedic clinic. Since bacterial activity and cytocompatibility are always contrary factors, it is hard to have them both in one material. The development of bioactive materials with a good bacterial character and without sacrificing biocompatibility and osteogenic activity, is an interesting and valuable research topic. In the present work, the antimicrobial characteristic of germanium, GeO2was used to enhance the antibacterial properties of silicocarnotite (Ca5(PO4)2SiO4, CPS). In addition, its cytocompatibility was also investigated. The results demonstrated that Ge–CPS can effectively inhibit the proliferation of bothEscherichia coli(E. coli) andStaphylococcus aureus(S. aureus), and it showed no cytotoxicity to rat bone marrow-derived mesenchymal stem cells (rBMSCs). In addition, as the bioceramic degraded, a sustainable release of germanium could be achieved, ensuring long-term antibacterial activity. The results indicated that Ge–CPS has excellent antibacterial activity compared with pure CPS, while no obvious cytotoxicity was observed, which could make it a promising candidate for the bone repair of infected bone defects.Keywords:implant material;silicocarnotite;germanium dioxide;antibacterial activity;cytocompatibility
Ce doped germanium dioxide nanowires with cubic GeO2 and tetragonal CeGeO4 phases have been synthesized by the hydrothermal route using sodium dodecyl sulfate (SDS) as the surfactant. The nanowires have the length and diameter of about 20 μm and 50–200 nm, respectively. The SDS assisted growth process is proposed to explain the formation of the Ce doped germanium dioxide nanowires. Ce doped germanium dioxide nanowires is used as the photocatalyst for the photocatalytic degradation of gentian violet (GV) under solar light irradiation. The roles of the solar light irradiation time, content of the nanowires and GV concentration on the photocatalytic degradation of GV are investigated. GV can be totally degraded under solar light irradiation for 240 min using 15 mg nanowires in 10 mL GV solution with the concentration of 10 mg · L−1. The Ce doped germanium dioixde nanowires show good application potential for the removal of organic pollutants under solar light irradiation. [DOI: 10.1380/ejssnt.2016.4]
Designing highly active nanozymes for bioanalysis and environmental sensing remains a challenge. In this study, transition metal, palladium (Pd) and iron (Fe), doped germanium oxide (GeO 2 ) nanozyme was designed and optimized. Compared with the pristine GeO 2 nanozyme, the transition metal doped GeO 2 nanozyme have lower Michaelis-Menten constants and higher catalytic activity , indicating that the Pd and Fe doped GeO 2 nanozyme not only enhance their affinity for the substrate but also improve its catalytic activity. In addition, a colorimetric sensor based on the GeO 2 @Pd–H 2 O 2 -TMB system was constructed for the visual detection of simazine in water samples due to the good affinity between TMB and simazine. This sensor has good selectivity and sensitivity with a detection limit of 6.21 μM because of the highest catalytic performance of GeO 2 @Pd nanozyme. This study broadens the application of nanozymes in environmental field and other nanozymes can also be enhanced in activity by simple transition metal doping.