Liquid crystals (LCs) with stimuli-responsive configuration transition and optical anisotropic properties have attracted enormous interest in the development of simple and label-free biosensors. The combination of microfluidics and the LCs offers great advantages over traditional LC-based biosensors including small sample consumption, fast analysis and low cost. Moreover, microfluidic techniques provide a promising tool to fabricate uniform and reproducible LC-based sensing platforms. In this review, we emphasize the recent development of microfluidics in the fabrication and integration of LC-based biosensors, including LC planar sensing platforms and LC droplets. Fabrication and integration of LC-based planar platforms with microfluidics for biosensing applications are first introduced. The generation and entrapment of monodisperse LC droplets with different microfluidic structures, as well as their applications in the detection of chemical and biological species, are then summarized. Finally, the challenges and future perspectives of the development of LC-based microfluidic biosensors are proposed. This review will promote the understanding of microfluidic techniques in LC-based biosensors and facilitate the development of LC-based microfluidic biosensing devices with high performance.

A Co₂P hybrid, containing Co₂P nanoparticles anchored on a P, N-doped porous carbon matrix, was synthesized and modified on a screen-printed electrode (SPE) as Co₂P hybrid-SPE for the simultaneous detection of ascorbic acid, dopamine and uric acid.

Electroporation shows great potential in biology and biomedical applications. However, there is still a lack of reliable protocol for cell electroporation to achieve a high perforation efficiency due to the unclear influence mechanism of various factors, especially the salt ions in buffer solution. The tiny membrane structure of a cell and the electroporation scale make it difficult to monitor the electroporation process. In this study, we used both molecular dynamics (MD) simulation and experimental methods to explore the influence of salt ions on the electroporation process. Giant unilamellar vesicles (GUVs) were constructed as the model, and sodium chloride (NaCl) was selected as the representative salt ion in this study. The results show that the electroporation process follows lag-burst kinetics, where the lag period first appears after applying the electric field, followed by a rapid pore expansion. For the first time, we find that the salt ion plays opposite roles in different stages of the electroporation process. The accumulation of salt ions near the membrane surface provides an extra potential to promote the pore initiation, while the charge screening effect of the ions within the pore increases the line tension of the pore to induce the instability of the pore and lead to the closure. The GUV electroporation experiments obtain qualitatively consistent results with MD simulations. This work can provide guidance for the selection of parameters for cell electroporation process.

Vitamins are essential and necessary nutrients for the human body. Rapid and accurate quantification of their levels in various samples has attracted much attention. Compared with traditional analytical methods, electrochemical techniques, with the advantages of low cost, high sensitivity, flexible detection strategies, easy integration, and miniaturization, have gradually become the main tools in vitamin detection. In this paper, the advance of electrochemical sensing of vitamins in recent years is reviewed. Firstly, the basics of different vitamins are briefly introduced. Then, the commonly-used electrodes and electrochemical methods for vitamin electrochemical detection, as well as the specific implementation strategy and performance, are described in detail. The development of miniaturization devices, especially microfluidic and microsensor devices, is also presented. Finally, the challenges faced by the electrochemical detection of vitamins are discussed, and future development is prospected.