The conservation of weathered historic sandstone with apatite was studied. Based on the growth mechanism of bone, calcium and phosphorus were introduced into weathered sandstone and then mineralized at room temperature. The conservation efficiency was investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), and compressive strength, capillary water uptake, water vapor permeability and weather resistance tests. The SEM, EDX, TEM, SAED and XRD results showed that the produced hydroxyapatite could reunite the weathered stone blocks and provide sufficient reinforcement to hold them together. The results of the various tests indicated that the compressive strength and weather resistance of the treated samples was improved significantly. In addition, because of the porous nature of apatite, the water vapor permeability of the treated stone was not affected and its breathability was maintained.

Nowadays, the emerging photoelectrochemical (PEC) bioanalysis has drawn intensive interest due to its numerous merits. As one of its core elements, functional nanostructured materials play a crucial role during the construction of PEC biosensors, which can not only be employed as transducers but also act as signal probes. Although both chemical composition and morphology control of nanostructured materials contribute to the excellent analytical performance of PEC bioassay, surveys addressing nanostructures with different dimensionality have rarely been reported. In this review, according to classification based on dimensionality, zero-dimensional, one-dimensional, two-dimensional, and three-dimensional nanostructures used in PEC bioanalysis are evaluated, with an emphasis on the effect of morphology on the detection performances. Furthermore, using the illustration of recent works, related novel PEC biosensing patterns with promising applications are also discussed. Finally, the current challenges and some future perspectives in this field are addressed based on our opinions.