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The tungsten bronze-type lead metaniobate (PbNb 2 O 6 , PN) is a promising material for high-temperature piezoelectric devices, while its application is limited by the difficulty in fabrication. In this study, the microstructure and electrical properties of Ca-doped PN and Ca, Mn-co-doped PN ceramics sintered at different temperatures were investigated. Doping promoted the formation of the originally metastable ferroelectric orthorhombic phase. This might be partly attributed to the increased lattice distortion of the orthorhombic phase in the doped samples compared to that reported for pure PN. However, in single Asite Ca-doped PN the ferroelectric orthorhombic structure showed a low stability and started to transform to paraelectric phase far below 300°C, resulting in unstable high temperature piezoelectric properties. Interestingly, such a phase transition was completely depressed by A-site Ca and multisite Mn-codoping, which also improved the piezoelectric performance (d 33 = 71 pC/N) and thermal stability in both structure and piezoelectricity. The better stability and performance of the co-doped samples were explained by the improved sintering behavior and poling efficiency as well as its ability to occupy different sites in the TTB lattice.

Protein phosphorylation regulated by protein kinases, as well as their dephosphorylation, is one of the most common post-translational modifications, and plays important roles in physiological activities, such as intracellular signal communications, gene transcription, cell proliferation and apoptosis. Over-expression of protein kinases is closely associated with various diseases. Consequently, accurate detection of protein kinases activities and their relevant inhibitors screening is critically important, not only to the biochemical research, but also to the clinical diagnosis and therapy. Nanomaterials, taking advantage of large surface areas, as well as excellent electrical, catalytic, magnetic and optical properties, have been utilized as target concentrators, recognition components, signal transducer or amplification elements in protein kinase related assays. This review summarizes the recent representative works to highlight the applications of nanomaterials in different biosensor technologies for protein kinases activities detection and their inhibitors screening. First, different nanomaterials developed for phosphoprotein/phosphopeptide enrichment and phosphate recognition are introduced. Next, representative works are selected that mainly focus on the utilization of nanomaterials as signal transducer or amplification elements in various protein kinases sensing platforms, such as electrochemical, colorimetric, fluorescent, and mass spectroscopy-based approaches. Finally, the major challenges and perspectives of nanomaterials being applied in protein kinases related assays are discussed.